A woman's dead body was found in the shower of a buck's party's apartment in Melbourne, but the men say they were "stitched up".
Police say the exact circumstances surrounding her death are unknown and the four men are now being interviewed.
She was dressed in blue denim shorts, a long sleeve black top and white trainers.
Four men were taken into custody and are being interviewed, police said.
The cause of death is still unknown.
When questioned by a reporter as to how the woman died, one man believed to be part of the buck's party responded: "dunno, you'll have to ask the police".
Some of the men were seen downstairs at the club between 2.30am and 3am.
The group of men had travelled from the NSW and ACT for the party.
Two of the men told Fairfax they went out to a football match before hitting the town.
The groom-to-be remained inside the hotel lobby, talking on his mobile phone.
The paper also reported that a hotel guest called "000" after members of the group reportedly found the woman collapsed in the shower.
Other women who stayed at the apartment overnight said they hadn't heard anything suspicious until the sound of sirens at 8am.
Detective Nick Densley said an autopsy would be performed as soon as possible.