• Gail and Tommy Sheridan
Tony Cumberbirch said he had seen Sheridan in a group of five people from Scotland in Cupid's club in the Swinton area of Manchester in 2002.
He also told the trial at the High Court in Glasgow he was asked to cross out Sheridan's name from a book recording who had come to the club.
The 53 year-old, from Manchester, was giving evidence at the former Scottish Socialist Party (SSP) MSP's perjury trial.
Mr Cumberbirch said Cupid's was "a swingers' club - wife-swapping for liberated adults" and he had worked there for around 12 years - but was visiting socially on the night he claims to have seen Sheridan there.
He said: "I think it was a Friday night. There were three lads and two ladies. I know now one of them to be Tommy Sheridan. I didn't know at the time.
"It was Tommy Sheridan, two lads and two lasses in the club. They were drunk. They were drunken Scottish customers as far as we were concerned."
He added that he hadn't "played" with the group at the club.
Mr Cumberbirch also described the two women with the man he said was Sheridan.
He said he thought one was Scandinavian and the other was "dark-skinned and a little bit chunky".
Two witnesses, Anvar Khan and Katrine Trolle, have previously told the trial they went to Cupid's with Sheridan and a third, Gary Clark, said he had been to a club in Manchester.
He said he saw Sheridan again later at a party in Wigan, hosted by a friend called Ian, but had gone to bed early, saying: "It wasn't our sort of party. They weren't our sort of people."
But he said he had been "as close" to Sheridan at the party as he was now in the courtroom.
The Advocate Depute, Alex Prentice QC, asked him how he later concluded that the man he had seen was Sheridan.
Mr Cumberbirch replied: "Everything from this to Big Brother."
Under cross-examination from Sheridan, Mr Cumberbirch told him: "You were in the club. I remember you. I'm not coming here to tell lies in a case about perjury. Think about it."
He also said he had removed Sheridan's name from a ledger as a "favour" for a friend called Robbie.
He said: "I was asked to cross a name out of the book because someone had signed in with your name. I was asked to do it as a favour and I did it."
Sheridan denies lying to the courts during his successful action against the News of the World in 2006, which followed the newspaper's claims that he was an adulterer who visited swingers' clubs.
He and his wife Gail, both 46, and from Glasgow, are accused of lying under oath during the action. They deny the charges.
Mr Sheridan won 200,000 in damages after the newspapers printed the allegations about his private life.
The trial, before Lord Bracadale, continues.