BERLIN (AP) — Berlin prosecutors say a well-known member of Berlin's Pirate Party confessed in a letter to killing a younger man before taking his own life.

Spokesman Martin Steltner said Thursday that 44-year-old Gerwald Claus-Brunner appeared to have slain the 29-year-old for "highly personal reasons," but declined to elaborate.

Steltner says Claus-Brunner killed the man, whose name wasn't released, on Sept. 15 in the victim's Berlin apartment, then moved the body to his own flat.

Both bodies were found on Monday.

The Pirate Party was founded a decade ago with a focus on internet freedom. It took only 1.7 percent of the votes in Berlin's state election Sunday, losing its seats in parliament.

Authorities say Claus-Brunner, who represented the party in the state parliament, likely died before election results were announced.