The Cosby Show star is facing a defamation suit filed in Massachusetts federal court by seven women, who have accused the comedian of calling them liars after alleging he drugged and/or raped or sexually assaulted them in decades-old incidents.

Cosby requested to have the case postponed until his criminal case in Pennsylvania involving another former accuser, Andrea Constand, was over, but a judge did not grant his motion on Monday (04Apr16).

However, the lawmaker did allow the discovery phase to be delayed in a bid to protect Cosby from incriminating himself in the criminal case.

The ruling comes a week after the 78-year-old was granted a delay in his second deposition relating to allegations he sexually assaulted Judy Huth in the 1970s.

Huth is one of more than 50 women who have come forward with accusations of inappropriate behaviour, drugging and/or rape against Cosby since late 2014.

The statute of limitations has expired in almost all of the cases, preventing the alleged victims from pursuing criminal charges, but Huth claims she was just 15 when the comedian reportedly forced himself upon her during a party at the Playboy Mansion in California in 1974.

Cosby is currently fighting an aggravated indecent assault charge for allegedly drugging and sexually assaulting former Temple University employee Constand at his Pennsylvania home in 2004.