Source of WA hospital lead found

The source of lead contaminating water at the unfinished, $1.2 billion Perth Children's Hospital has been identified, the WA government says.

Treasurer Mike Nahan told parliament on Wednesday the lead was not coming from the new building.

He told parliament on Wednesday that the source of the contaminated water appeared to come from a new pipe installed under a road and further tests were being conducted.

On Tuesday, Building Commissioner Peter Gow issued an interim report into asbestos found inside ceiling panels at the hospital, saying builder John Holland was not to blame as Chinese building products company Yuanda had provided a certificate labelling the sheeting asbestos-free.

Yuanda then said a supplier had provided it with the hazardous substance without its knowledge, despite the company specifying it wanted asbestos-free sheeting.