The criminal case against Bill Cosby has been thrown into doubt following the emergence of a recent email that says a crucial civil deposition given by the actor 10 years ago can not be used in any criminal case against him.
Cosby, who faces three felony charges of sexual assault, gave the deposition in 2005 in which he admitted he had slept with five different women outside of his marriage and used sedatives to drug them.
The email, discovered by CNN, was sent in 2015 and written by a former district attorney in Montgomery County. It allegedly describes a verbal agreement the prosecutor had with Cosby's attorneys about his 2005 sexual assault case.
In it, the attorney referred to a 2005 understanding that Cosby's deposition would not be used in any criminal matters. The email, sent three months before criminal charges were filed against Mr Cosby in 2015 and written by District Attorney Bruce Castor, says: "I can see no possibility that Cosby's deposition could be used in a state criminal case, because I would have to testify as to what happened, and the deposition would be subject to suppression."
The deposition was given as a reason for re-opening the case against Cosby.
Mr Castor continued, "I cannot believe any state court judge would allow that deposition into evidence. .... Knowing this, unless you can make out a case without that deposition and without anything the deposition led you to, I think Cosby would have an action against the County and maybe even against you personally."
Bill Cosby: Career in pictures
Bill Cosby: Career in pictures
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Winner of his first Emmy for 'I Spy' is Bill Cosby being congratulated by his wife Camille held at Americana Hotel, 1966
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Bill Cosby in 'I Spy', 1960s
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Bill Cosby in July 1973 in Perth
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Bill Cosby and Richard Pryor in 'California Suite', 1978
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Bill Cosby and Elmo in Sesame Street, 1989
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Bill Cosby poses for a picture with Florence Griffith-Joyner in June 1989
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Comedian Bill Cosby back in 1992
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A scene from a 1992 episode of 'The Cosby Show'
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US Monica Seles breaks into laughter as she jokes with comedian Bill Cosby during a celebrity match in the stadium at the US Open for the Arthur Ashe AIDS Challenge on 27 August 1995
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Bill Cosby meets Toronto Blue Jays' All-Star Joe Carter after the Stars played the Stripes in the Celebrity All-Star game which preceded workouts for the 67th All-Star Game at Veterans Stadium on 8 July 1996 in Philadephia
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Co-hosts Oprah Winfrey and Bill Cosby joke with each other during the opening of the 2000 Essence Awards 14 April 2000 at Radio City Music Hall in New York City
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Bill Cosby jokes with baseball great Hank Aaron after they both received the Presidential Medal of Freedom Award from U.S. President George W. Bush during a ceremony on 9 July 2002 at the White House in Washington
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Bill Cosby poses backstage after winning the 'Bob Hope Humanitarian Award' during the 55th Annual Primetime Emmy Awards at the Shrine Auditorium on 21 September 2003 in Los Angeles
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'Tonight Show' host Jay Leno and comedian Bill Cosby laugh during a surprise visit by Cosby to sign a Harley-Davidson motorcycle that Leno is using to raise money for the victims of Hurricane Katrina at NBC studios on 9 September 2005 in Burbank, California
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Bill Cosby speaks during a taping of 'Meet the Press' at the NBC studios on 14 October 2007 in Washington
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Bill Cosby at the 12th annual Mark Twain Prize for American Humor at the John F. Kennedy Center on 26 October 2009 in Washington
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Bill Cosby speaks at the National Action Network's 20th annual Keepers of the Dream Awards gala in New York on 6 April 2011
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Bill Cosby during the 100th anniversary celebration of the Beverly Hills Hotel & Bungalows supporting the Motion Picture & Television Fund and the American Comedy Fund, 2012
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Bill Cosby speaks onstage at the Thurgood Marshall College Fund 25th Awards Gala on 11 November 2013 in Washington
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Bill Cosby performs at the Treasure Island Hotel & Casino on 26 September 2014 in Las Vegas
The sexual assault case is based on claims made by Andrea Constant, who says Cosby assaulted her in his home in 2004.
Ms Constant’s case became the centre of the furore surrounding Mr Cosby - more than 50 women claimed that he drugged or assaulted them. Mr Cosby admits to sleeping with women extra-maritally, but denies allegations of underage sex or abuse. The case continues.