Colleagues of Peta Credlin are shying away from allegations she had an affair with Tony Abbott.

Australian Journalist Niki Savva has recently published a book claiming the pair had a fling while he was in government.

Australian Correspondent Steve Price says not one woman who worked in the government while she was chief of staff has defended her.

"Not one had the courage to stand up yesterday, defy Malcom Turnbull, defy this woman who's written this book and say it never happened."

Steve Price says the contents of the book remain unproven.