The order from the court issued on Friday does not elaborate on the decision.

Cosby filed an appeal earlier this month saying that Pennsylvania trial Judge Steven O'Neill had a feud with a key pre-trial witness, the former county prosecutor who declined to arrest Cosby a decade earlier.

And they say his decision to let five other accusers testify among other alleged issues are grounds for a new trial.

A jury convicted the 81-year-old Cosby in April of drugging and molesting a woman in 2004.

The legally blind comedian is housed in a new state prison about 30km from his Philadelphia-area estate.

Australian Associated Press