A man and woman from Sydney, who are accused of sexually assaulting their nine-year-old son, have been remanded in custody.

The 56-year-old man, who is facing six charges, was the first of the two to appear at Sutherland Local Court today.

He was led barefoot into the dock where he listened as the magistrate told him that police had served an Apprehended Violence Order (AVO) on him, forbidding him from contacting his son.

Documents tendered to the court allege that the couple raped their nine year old son and streamed the video live on the internet using a webcam.

They were arrested last night at their home at Peakhurst, in Sydney's south, where police say they found two computers containing the pornographic images.

The boy's mother, aged 46, said nothing during her appearance as the magistrate repeated the same instructions regarding the AVO.

She cannot call or write to her son from jail.

The woman faces charges of sexual assault and aggravated indecent assault.

She also faces charges of concealing a serious offence and inciting an act of indecency.

The police documents state that she knew her husband was raping her son and she failed to report it.

It is alleged that the assaults happened sometime between New Year's Day and a week ago.

The matter returns to court next year.