Mikhail Sindeev was one of the original creators of Huntercoin.
A couple of weeks after Huntercoin launched, it was announced that Mikhail had died of a stroke at age 27. Fatal strokes are rare among people under 40, so there was suspicion, even among those who did not understand why 'real' ai would be important.
In the early history of post bitcoin digital currencies there were a few suspicious deaths, but Mikhail's stands out.
There are two broad paths artificial intelligence could follow.
1) Corporate artificial intelligence is what Google and most governments are selling to the public as 'artificial intelligence'.
This is simply software intended to mimic human learning, with its ultimate goal being to create a plausible 'false human' within some technological framework. In other words the goal is for individuals to project onto technology, to relate to computers etc as if they were sentient. This gives the designers of those 'humanized interfaces' a lot of control over the people who they convince to project onto the electronics.
"Projection. An automatic process whereby contents of one's own unconscious are perceived to be in others."
Any software provides some sort of interface between a person and the abilities of a computer, though usually pretending that the computer is human is not part of the objective. You don't really care if a device, a computer, an alarm clock, a stove, etc acts like it is a human, if it talks or whatever. The 'learning' referred to by practitioners of this type of ai is not actual learning, it is mimicking, exactly the same as any software. The so called 'deep learning' and all the other glamorous catch phrases are nonsense, they are a software step that is, at best, trivial, in terms of generating intelligence. They are useful for controlling, deceiving etc, because they are presented as 'intelligence' rather than 'tool'.
In other words the 'teaching computers to learn' facet is false, a tiny step in software development. But the 'humanizing computers' aspect is the real, deceptive, endpoint which corporate ai is after.
Are computers really human? Are they sentient? Do they learn? Of course not. If you create a circuit that mimics aspects of a person, is that circuit now on a path to sentience? No.
In fact the biggest step in 'computer learning' was an early step, giving computers access to previous calculations they had made, a memory of sorts. Refining the calculations that memory uses, then pretending it is a big step on account of its design being made to appear 'human like' is silliness. It is a deception which catches a lot of people because industrialized people are already trained to project human attributes onto non human objects. It is a variation of the 'primitive' tendency to personify natural objects, with the difference being that the latter tendency, among 'primitive' people, evolves. Industrial ai creates psychological captives, not evolving people.
A person might argue that humans are the product of a collection or series of mathematical arrangements of chemical sequences, but the difference is that those sequences arose within a large ecosystem. Fake ai is like going to a school and giving guns to the kids you think should have power. Real ai is more like simply making guns available equally.
2) Genuine new artificial intelligence is the use of some new tool to generate intelligence. A person using any tool which provides any additional data or otherwise 'increases' the intelligence of the 'person + tool' combination relative to 'only person, without tool' is artificial intelligence. As mentioned before, almost any software or hardware can be an artificial intelligence tool.
2a) The use of human input networks to develop any science using algorithms is a new kind of ai which first became evident to a lot of people when the digital currency Huntercoin was developed. This kind of 'real' ai, i.e., a real new step, empowers small groups. Potentially any small group could use an incentivized digital network to develop any science, any progression of knowledge which follows rational rules.
So artificial intelligence has existed for a long time, the abacus was an ai tool thousands of years ago, but the phrase 'artificial intelligence' has not existed a long time.
Those who present software, i.e. what Google and governments call 'artificial intelligence', as a modern new 'artificial intelligence' are misguided or worse.
In addition to being the main force behind Huntercoin, Mikhail Sindeyev was also involved with Namecoin, another politically sensitive project. Namecoin offered an alternative system for routing community traffic outside the control of corporations and governments.
Like Huntercoin which followed it, Namecoin created a stir among people who recognized that it would attract negative government attention if it gained traction.
Namecoin is considered the first 'altcoin' because it was the first digital currency created after bitcoin.
Governments have been heavily involved in digital currencies of course.
New currencies have important political implications, and bureaucrats like to be in control of such things, so they can feel powerful as they mumble nonsense.
Early Huntercoin was clearly meant to break into the field of network artificial intelligence, something very different from the corporate ai promoted by companies like Google and most governments.
Mikhail was studying cybernetics and he and his colleagues had published papers that clearly focused on artificial intelligence.
So it was clear his intentions went beyond simple gaming.
After his death, a number of unusual links and articles popped up, some of which are still available. The appearance was that somebody or some organization was creating a smokescreen behind his death.
There are three obvious government actors which might have had reasonable motive to eliminate him.
1) The Russians are famous in the West for hiring clumsy hitmen who leave a mess and operate on very weak local or personal motives. In this case Sindeev was a PhD level student/teacher in Russia and the Russian government had complete access to him, so unless he were dangerously 'anti government' it is unlikely they would kill him.
Was he anti government?
His Twitter profile, strangely, has a post made after his death, and the Russian phrase "Soul in Bali, body in Saint Petersburg" in the bio.
One of the people following him, and who he follows, is a girl named Alena Shipovskaya https://twitter.com/yashipovskaya
Alena is only following 8 people, and 6 of those are celebrities. So she is following two 'real' people, Mikhail and a character called Cocaine Spider  That person's profile motto on Twitter is "Don't be a pussy!" which makes it more likely the person is some kind of government employee. Regular protestors of authoritarian rulers don't usually post banners like that, but people trying to maneuver their way into anti authoritarian groups more often do. It's also possible he or she is a real protestor who is posturing for their own reasons.
Alena made two posts shortly after Mikhail's death, then stopped using Twitter.
March 25, 2014 "At the moment, I can't imagine what could be tastier than hot smoked mackerel." 
Those two people who intersected Mikhail shortly before his death have some history of association with Navalny protests going back a ways, but it isn't clear what https://imrussia.org/en/analysis/3216-crime-and-exposure
Twitter is a U.S. based corporation and is available to the U.S. government, but not most other governments, for projects. The U.S. has full access to all Twitter accounts and history, other governments not allied with the U.S. do not, except for regular law enforcement.
A person interested in researching possible Russian involvement would try to find out how real those characters are, and what happened to them.
2) The British might have had a more strategic motive. Mikhail's early partner on the coin was a Brit, and after Mikhail's death he was replaced by a German. Early in its history huntercoin received wide publicity and was extremely popular, before it fizzled. The British had little or no control over Mikhail, and his replacement by a West European would have made any interference by them easier.
The British are much more discreet about political killings than the Russians. The easiest way to research possible British involvement might be to research 'Mikhail #2' who made a website called 'football without wives' mentioned below. If that character does not have a legitimate real world history under that name then it would cast a shadow on the British.
Mikhail's involvement with Namecoin would also tend to point suspicion at the British, who are heavily vested in the current dns system.
3) The Chinese have an obvious interest in collaborating with the Russians in ai development, as rivals to the West. In the years before Huntercoin, Mikhail's larger circle of colleagues had a number of academic papers produced in collaboration with Chinese academics, some from the mainland, some from Hong Kong and some abroad. Killing Mikhail would have nipped a potentially huge connection between the Russian ai community and the Western European ai community, if Huntercoin had become successful. It's unlikely the Chinese had the resources to do something like that in Russia though. And anyway China is known for killing Falun Gong and harvesting their organs, but not for strategic scientific murders abroad.
So, at first glance Mikhail could have been killed by the Russians, the British or the Chinese.
Google searching the image from the 'real' Mikhail's bio, there is a link to another blog vaguely suspecting foul play 
It's important to see also that 'nationalistic killings' i.e. murders committed 'by a state' are not actually committed by that state, they are committed by a group of isolated individuals acting on personal motives under guise of acting for a state.
People who have lower motives and unresolved group issues are often drawn to working for a larger organization, such as a government, which will give them the ability to work out issues which they could not work out on their own.
If Huntercoin had taken off, and if it had been piled into by people interested in ai, it would have quickly outrun the corporate ai type projects being pushed by Google and melting pot governments. It would have been what bitcoin lamely pretends to be.
Independent network ai lets any group quickly develop considerable power, depending on their education, and could be used as a tool to form hard, and powerful, economic borders for tribal groups, along with competitive rivalry.
So, aside from developing sciences rapidly, including those which might be important to face the various emergencies the world is facing, ai network currencies would threaten the ability of melting pots to control tribal groups.
The various 'most threatened' tribal groups around the world are not known for their conventional scientific expertise, but their supporters are, and the nature of the digital economy would most likely lead to a rapid increase in the real world power of those groups, initially via their supporters.
At some point in the future distinct tribal groups with a non melting pot worldview will have an advantage in ai.
The tribal paradigms those groups would provide, if they can be empowered before being polluted by the global melting pot paradigm, would have amazing and unknown effects on science. Where today people wonder about trivial paradigm conflicts, introducing secure sovereign tribal worldviews into the science community would be opening up worlds melting potted people cannot even imagine.
It is certain that ai network coins, using monetized networks like 'digital currencies' will utterly crush the fake ai being developed by corporate melting pot interests. It's also clear that corporate interests are aware of this threat to their dominance. What isn't known is how those corporate/melting pot interests will respond once those networks start popping up. In the context of recent political history it is a safe guess that they will be presented to the public as akin to terrorism in some way. In other words the single best chance to rapidly develop sciences in the modern world will probably be presented to the public as terroristic or dangerous enterprises when they start.