Bill Cosby's attorney has vowed to go after the lawyers representing two alleged sexual assault victims who have filed lawsuits against the embattled comedian.

More than 20 women have come forward with damning accusations against The Cosby Show star in recent weeks, and Judy Huth became the first to sue last week (begs01Dec14) amid claims he got her drunk and then raped her during a party at the Playboy Mansion in Los Angeles in 1974, when she was just 15.

A second woman, Tamara Green, followed suit with defamation papers on Wednesday (10Dec14), accusing the funnyman of lying about his contact with her.

She maintains Cosby drugged her during a lunch date in the early 1970s and then groped her at her apartment.

His attorney, Marty Singer, has repeatedly denied her allegations, which Green claims have subjected her to public and private ridicule.

Explaining the reasons for the defamation action, her lawyer, Joseph Cammarata, tells ABC News, "She realised that there was an opportunity to have her allegations against Mr. Cosby heard in a court of law, where the truth can be tried."

However, Singer is determined to fight the claims to the fullest extent of the law - even if that means going after the lawyers themselves.

In a statement issued to U.S. breakfast show Good Morning America, he writes, "We are very confident that we will prevail in this proceeding and we will pursue claims against the attorneys who filed this action."

Cammarata previously represented Paula Jones in her sexual harassment suit against former U.S. President Bill Clinton in 1994. That case was settled out-of-court for a monetary fee, before the lawsuit was dismissed after Jones failed to demonstrate damages. The legal action eventually led to Clinton's impeachment in 1998. He was acquitted in 1999.