A former Montgomery County ­prosecutor’s purported promise not to prosecute Bill Cosby was once again central to the comedian’s criminal case Tuesday, as defense attorneys argued for suppression of evidence from a 2005 deposition.

Lawyers for Bill Cosby argued Tuesday that Cosby relied on a promise he would never be prosecuted when he sat for the deposition, at which he admitted to obtaining drugs in order to have sex with a woman. The arguments were made as part of two days of hearings scheduled to deal with evidentiary issues in Cosby’s pending criminal trial.