A female acquaintance of comedian Bill Cosby (search) has leveled an allegation against him that has prompted a police investigation in Philadelphia, the entertainer's attorney said Thursday.

Attorney Walter Phillips (search) wouldn't discuss the specifics of the allegation but said it amounts to, at the most, "inappropriate touching."

No charges have been brought against Cosby, but Phillips said authorities have begun an investigation. He said the accuser, who lives in Canada, knows Cosby and the alleged incident in question happened about a year ago. He called the allegation "utterly preposterous."

"I know the person making the accusation hasn't been contacted by authorities," Phillips said in a telephone interview with The Associated Press. "We are hopeful and optimistic that no charges will be brought forward."

Philadelphia police and Canadian authorities declined to comment.

Meanwhile, Cosby postponed a town hall meeting in Cleveland on Thursday and has postponed three upcoming shows — two in Ft. Lauderdale and one in Daytona, both in Florida, Cosby's publicist, David Brokaw, said.

Brokaw wouldn't say whether the postponements have anything to do with the recent allegation.

About 3,600 people, including many Cleveland public school students and their parents, received free tickets for the event at the downtown Music Hall, part of the Cleveland Convention Center (search).

"I feel awful about it," said Sam Fulwood, a (Cleveland) Plain Dealer columnist, who said he received a personal call from Cosby requesting help organizing the event.

Fulwood said he has not heard from Cosby directly since learning of the postponement Wednesday night.

"He's not talking right now," Fulwood said.