Hammersmith Station was closed during the alert
The station and surrounding roads were closed while emergency services dealt with the scare at about 0825 BST.
The alert comes amid a raised security threat following the failed terrorist attacks in London and Glasgow.
There was an unconfirmed report that the suspect objects had turned out to be three abandoned fire extinguishers.
"These are the kinds of challenges we face in London every day," said Ch Supt Ali Dizai. "We can't afford to take any chances."
Up to 8,000 commuters were forced to find alternative routes into work as Hammersmith and Barons Court stations were closed for an hour.
There were severe delays for motorists as Hammersmith Broadway was closed between King Street and Shepherd's Bush Road as well as Hammersmith Bridge.
Tower Hill and East Ham Tube stations, which were shut in a separate alert, have also reopened.
New Scotland Yard, the headquarters of the Metropolitan Police Force
A suspicious bag has undergone a controlled explosion outside a London Underground station, as has a car outside a mosque in Glasgow, Scotland.

These police actions come in the wake of failed terror attacks involving car bombs in London and at Glasgow International Airport on 29th and 30th June.  

The terror threat level in the UK remains ''critical'', indicating that an attack could be expected imminently and high security is in evidence on mass transport routes, while the police continue their investigations.  Earlier this morning, a controlled explosion took place on a suspicious package discovered outside Hammersmith Station on the London Underground system. The scare led to the closure of Hammersmith and Barons Court stations for one hour. 

Two other stations, Tower Hill and East Ham, were closed in similar circumstances. All four stations have now been reopened.

Sky news reports that three controlled explosions took place on a car outside a mosque in Glasgow, in order to allow police to gain entry to it. The mosque itself is not being linked to the terror attacks.

The Muslim Council of Britain has condemned the attacks, and has urged Muslims throughout the country to assist in police investigations.

The police force is continuing its investigations throughout the country, with an open appeal to the country for vigilance in reporting anything suspicious.