Reports indicate that a piece of evidence in the sex assault case against Bill Cosby has been called into question.
The evidence in the form of an email seen by CNN alleges that a prosecutor promised Mr Cosby's deposition in a 2005 civil case would not be used to bring criminal charges.
In the deposition, Mr Cosby admitted drugging women during sexual encounters but said it was by mutual consent. The deposition now forms the basis of an aggravated indecent assault charge.During the civil claim deposition, Mr Cosby admitted giving Ms Constand wine and pills but said she consented to take them. He also admitted paying off other women to keep them quiet.
Mr Cosby has however denied the charge and his lawyers will now use the immunity claim to get the case dismissed.
Former Montgomery County district attorney Bill Castor was in charge when Andrea Constand sued Mr Cosby in a civil sex assault trial in 2005, after no criminal charges were brought. Mr Cosby settled the case for an undisclosed sum.
According to CNN, Mr Castor, agreed that Mr Cosby's civil deposition would not be used to bring criminal charges against him, but however the current district attorney, Kevin Steele, said there is no evidence of a signed immunity agreement, which would have had to go through agreed channels.
The Associated Press news agency reported that on Saturday, Andrea Constand's lawyer said she never knew of such an agreement.
Mr Castor will be called by Mr Cosby's lawyers at a hearing on 2 February, where they will attempt to get the charge dismissed but the current district attorney, Kevin Steele, said there is no evidence of a signed immunity agreement, which would have had to go through agreed channels.
Mr. Cosby has been accused by dozens of women of sexual assault, dating back to the 1970s, but only one charge has been brought because of the statute of limitations has passed on the majority of claims.