Clooney's press representative, Stan Rosenfield, told The Associated Press on Thursday: "Rumors are rumors."
Pitt's representative, Cindy Guagenti, declined to comment.
Reports about an impending wedding at the northern Italian lake were rife last year, but quickly fizzled out after Clooney denied his friends were scheduled to marry at his villa.
Meanwhile, Monica Mantero, the wife of Laglio Mayor Giuseppe Mantero, said Thursday her husband could marry the couple on an hour's notice.
"There's a lot of movement at the villa, a lot of people there. We were expecting Clooney today but he didn't show up," Monica Mantero told the AP.
She said Pitt and Jolie hadn't fixed a date with her husband, but that "even if they contacted him an hour before he could still marry them."
Mantero, who lives across from Clooney's villa, said preparations taking place on the grounds were the ones routinely done ahead of the actor's arrival. She added that a reception in the garden didn't seem to be in the works.
"I can tell you Clooney isn't here (in Laglio), because whenever he's here a motorboat is tied up to his dock and there's no motorboat. I'm looking right now from my window," said Mariuccia Riva, whose husband's boatyard often rents boats to Clooney's guests.
Jolie — who starred alongside Pitt in the 2005 film "Mr. & Mrs. Smith" — is expecting his child this summer. Pitt and Jennifer Aniston.
Another rumored location for the marriage is a luxurious hotel in the nearby town of Cernobbio that often hosts stars and international conventions.
"We don't have any booking under their name, but if they show up we'll be happy to take them in," said Annamaria Duvia, a spokeswoman for the Villa D'Este resort.
"Of course I can't rule out they've booked under a false name," she told the AP.
Giuseppe Salvioni, a spokesman for Cernobbio city hall, said there was no official indication of an upcoming ceremony.