BOSTON >> Two Florida women accusing Bill Cosby of sexual offenses decades ago have joined a defamation lawsuit, contending he publicly branded them as liars through statements by his representatives.

The amended federal complaint was filed Monday in western Massachusetts, near where Cosby has a home.

The lawsuit was filed last month by Tamara Green, who said Cosby drugged and assaulted her in the 1970s. The new plaintiffs are Therese Serignese, who said Cosby raped her in 1976, and Linda Traitz, who alleges Cosby groped her in 1970.

Cosby’s publicist David Brokaw and lawyer Martin Singer didn’t immediately respond to requests for comment. Singer has said he expected to prevail in the original lawsuit.

Since November, at least 15 women have said Cosby sexually assaulted them decades ago. He’s never been charged.