Xie's wife feared evidence 'plant' by cops

The wife of Robert Xie, the man accused of slaying five of her relatives, feared police would plant incriminating evidence and use her husband as a scapegoat, a court has heard.

Kathy Lin took the stand at her husband's Supreme Court murder trial on Monday, telling the jury she had wanted items from their home independently tested rather than tested by police.

Xie has pleaded not guilty to the July 2009 murders of Ms Lin's brother, Norman Lin, his wife Lilly, their two sons, and Lilly's sister Irene at their North Epping home.

Ms Lin answered "yes" when asked if she had believed she might be arrested over the murders as police investigators focused on her husband.

She said she had been "very upset and very angry" over the police investigation, and felt as if she were being treated "like a criminal, not a victim".

She said on Monday she was "scared the police would plant evidence against us" and use her husband as a "scapegoat".

Such were her concerns, she told the court, that she had wanted to give items sought by police, including Xie's clothing, to independent testers.

The trial continues.