Clemens' former trainer, Brian McNamee, said the seven-time Cy Young Award winner was at the party. Clemens denied being there when he gave a deposition to congressional investigators on Feb. 5, then testified eight days later that it was possible he could have stopped by after playing golf.
In the Mitchell Report on doping in baseball, released in December, McNamee alleged that Clemens spoke with Canseco at the barbecue and soon after approached the trainer about using performance-enhancing drugs.
McNamee said he injected Clemens with steroids and human growth hormone at least 16 times, possibly more, between 1998 and 2001. Clemens has vehemently denied those accusations several times, including under oath before Congress.
Congress is deciding whether to ask the Justice Department to investigate the contradictory testimony given by Clemens and McNamee under oath. Whether Clemens attended Canseco's party could affect both his and McNamee's credibility.
Clemens and Canseco played for the Toronto Blue Jays in 1998.
Clemens' lawyer, Rusty Hardin, said in a statement Friday that on Feb. 12 he was contacted by a former neighbor of Canseco's.
"He said he had a photograph of his son with Roger in a pool at a party at Canseco's house. He said that friends who had seen the photograph were suggesting to him that he sell it. I expressed no interest in buying it, but urged him to let our investigator visit with him, view the photograph and interview him. He said he wanted to talk to his son first and would call me back that day. I gave him all of my phone numbers and urged him to call. Unfortunately, I never heard back from him," the statement said.
"It is impossible for us to comment on the photograph itself because we haven't seen it. We know that baseball announcers broadcasting the games at the time said Roger was not at the party. Jose Canseco has said Roger was not at the party, as has Canseco's former wife. Roger was playing golf at the time of the party, and has stated that he may have stopped by the Canseco house after playing golf before heading to the ballpark for the game."
McNamee's lawyer, Richard Emery, said Friday he didn't have the photo but thought at some point it would be obtained by the congressional committee and/or prosecutors.
The photo's existence was first reported by the Daily News.