Bill Cosby thanks Eddie Murphy for refusing to impersonate him on Saturday Night Live

The film star was asked to do the impression for show's 40th anniversary

Bill Cosby has expressed his gratitude to Eddie Murphy for turning down the opportunity to impersonate him in a sketch for Saturday Night Live’s 40th anniversary.

The embattled comedian has faced a string of sexual abuse allegations, which he denies, resulting in the postponement of several scheduled shows.

“I am very appreciative of Eddie and I applaud his actions,” Cosby told NBC through a spokesperson.

Kenan Thompson portrayed Cosby in the skit eventually aired last weekend but former cast member Norm Macdonald has since revealed Murphy was the writers’ initial choice.

He tweeted behind the scenes stories from the week at Saturday Night Live’s (SNL) Studio 8H for two hours on Wednesday, including chronicling how he, Lori Jo Hoekstra, and Steve Higgins wrote the Celebrity Jeopardy segment.

The “video daily double” part would have been taped six months earlier and left out direct references to the Cosby scandal, instead featuring him as a bartender mixing cocktails.

Bill Cosby performing stand-up in November

Murphy, who was a regular SNL cast member from 1980 to 1984, reportedly refused to do the impression because he “didn’t feel comfortable”.

Macdonald wrote on Twitter that he was given the job of convincing the film star to do Jeopardy.

“We talk in his dressing room a good hour,” he wrote.

“When it's over, I'm convinced he'll do it. He doesn't.

“He knew the laughs would bring the house down. Eddie Murphy knows what will work on SNL better than anyone.

“Eddie decides the laughs are not worth it. He will not kick a man when he is down.

“Eddie Murphy, I realise, is not like the rest of us. Eddie does not need the laughs.”

Macdonald, who appeared on SNL for five series starting in1993, went on to describe the comedian as the “coolest - a rockstar even in a room with actual rockstars”.

Murphy did eventually appear in the  40th anniversary special but made brief speech following a tribute by Chris Rock rather than doing sketches.