A powerful Swedish financier got blackout drunk at a house party and exposed his private parts to other guests — leading him to resign as a senior adviser to Citigroup on Monday, according to reports.

Anders Borg — who was once Sweden’s minister of finance — also reportedly threatened guests, groped other men and called female revelers “whores” and “sluts” during his night of debauchery, a source at the party told the Swedish tabloid Aftonbladet.

Borg’s antics were so alarming that Swedish police reportedly are investigating him for sexual harassment and making threats — and the 49-year-old money man issued a groveling mea culpa in which he claimed he was under extreme “pressure.”

“I have been told afterwards that I behaved very inappropriately,” he said in a Facebook post. “I sincerely apologize to all who were affected . . . I don’t drink more than most people but I have been under a lot of pressure lately.”

The exec allegedly launched into his rant after he was asked by the host of the bash to sleep in another home nearby, on the tiny Swedish island of Husaro, Aftonbladet reported.

There were about 50 people at the bawdy bash, which took place sometime in late July, according to the Financial Times.

Borg was hired by Citigroup in 2015 following his eight-year tenure at Sweden’s Finance Ministry as a senior adviser focusing on Europe, the Middle East and Africa.

On Sunday night, he also stepped down as deputy chairman of technology investment firm Kinnevik.

He said he was so hammered, he couldn’t remember what happened at the party.

“In a situation with a great deal of attention in the media, I choose to leave my mission as Vice-Chairman of the board of directors of the Kinneviks and board member,” he wrote in the Facebook post.

Borg — who insisted he did nothing wrong and blasted “rumors” — later explained the apology was “about me being rude” and “not to be interpreted as a recognition of crime.”

He is the chairman of an initiative on global finance at the World Economic Forum. “We are following the developments closely,” WEF spokeswoman Muzi Li told The Post on Tuesday, declining to comment further.

The money man was blasted Monday by a member of the same Swedish political party of which he is a member.

Anna Kinberg Batra, head of the Moderate Party, called the claims against Borg “very serious” and publicly welcomed the police investigation, according to the Financial Times.

Borg, however, blasted back at her, saying he was “deeply disappointed.”