WA govt eyeing John Holland 'like a hawk'

John Holland's poor performance so far building the new Perth hospital means it will now be watched closely, WA Treasurer Mike Nahan says.

WA Treasurer Mike Nahan (pic) has criticised builder John Holland over performance issues. (AAP)

The West Australian auditor general is investigating complaints by sub-contractors working on the new Perth Children's Hospital that they have not been paid as the state government said it was watching head contractor John Holland "like a hawk".

WA Treasurer Mike Nahan said the building giant had mismanaged the hospital project and that the state government would be watching them closely.

Hundreds of sub-standard fire door frames and water piping with defects have had to be replaced.

"This is a project that has been plagued by process problems of a high and ongoing magnitude," Mr Nahan told ABC radio.

Mr Nahan said he would be sitting down with newly appointed health minister John Day in coming days, to discuss the growing list of issues with the new hospital and his concerns John Holland was unloading them on its sub-contractors.

"Am I concerned that John Holland may pass its problems unduly onto subbies? Yes, I am monitoring that because it's a possibility."

A spokeswoman from the auditor general's office said the probe's findings would be presented to parliament by the middle of this year.

John Holland was contacted for comment.