Anders Borg, a former Moderate politician who was Sweden's Finance Minister in the Fredrik Reinfeldt government between 2006 and 2014, released a statement on his official Facebook page on Friday, following reports about the party in several Swedish tabloids.
"I was at a party at the weekend and suffered a blackout. I don't drink more than most but have been under intense pressure in recent months and it must have taken its toll," Borg wrote.
"I was informed afterwards that I conducted myself very inappropriately. I want to apologize sincerely to those present who were offended. I feel a great disappointment and regret over my behaviour," he added.
Though Borg did not specify what happened at the party, tabloid Aftonbladet cited details from several anonymous sources who alleged that it included being aggressive and using foul language towards other guests.
Borg now works in the finance world including as deputy chairman for investment firm Kinnevik and as a senior adviser to Citibank.
The Local contacted Anders Borg for comment.