Jan 1 (Reuters) - In the same week that comedian Bill Cosby was arrested on sexual assault charges, his wife, Camille Cosby, learned she must testify in a civil case against the entertainer filed by seven women who said he defamed them, court documents said.

A federal magistrate judge in Massachusetts on Thursday rejected arguments by Cosby's wife of almost 52 years, who also has been his business manager, that the deposition would represent an "undue burden."

The deposition is scheduled for next Wednesday, a week after Bill Cosby, 78, was charged in Pennsylvania in the only criminal case brought against the actor, who has been accused by more than 50 women of sexually abusing them in incidents dating back decades.

Cosby is free on $1 million bail, and his lawyer has said the entertainer is not guilty and will not consider a plea bargain.

Cosby, who exemplified the model family man in his long-running hit television series "The Cosby Show," was charged with aggravated indecent assault, which carries a maximum penalty of 5 to 10 years in prison.

The charge stems from accusations by Andrea Constand, 44, a former basketball team manager at Temple University in Philadelphia, Cosby's alma mater. She settled a civil case against Cosby for an undisclosed sum in 2006.

The Massachusetts civil lawsuit against Cosby was filed in December 2014 by Tamara Green, later joined by six other women, who contend that Cosby sexually assaulted or abused them, that each publicly accused Cosby, and Cosby responded by calling the women liars, thus defaming them, court documents said.

U.S. Magistrate Judge David Hennessy also rejected arguments by Camille Cosby that she lacked any first-hand knowledge of the events at issue, and that the court should protect her from "unnecessary harassment" by limiting the scope of the subpoena.

Lawyers for Bill Cosby plan to appeal Hennessy's ruling, according to the New York Times. (Reporting by Mary Wisniewski in Chicago; Editing by Peter Cooney)

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