Nothing untoward in Buswell claim: Barnett

Western Australia's premier says there was nothing untoward about former treasurer Troy Buswell's insurance claim for his crashed ministerial car.

Mr Buswell quit cabinet following revelations he had a mental breakdown after crashing into parked cars, a pole and the front gate of his Subiaco home while returning from a wedding in the early hours of February 23.

On Wednesday, the state opposition released documents obtained under freedom of information showing the incomplete claim form to government insurer RiskCover was not submitted or signed by Mr Buswell.

It was instead stamped by the director of state administration Kathryn Andrews.

Opposition spokesman Ben Wyatt said on Wednesday Mr Buswell should have signed the form himself as it required a driver's declaration and he was back at work in his Vasse electorate at the time.

Briefly returning from holiday to unveil the new Perth Stadium design on Thursday, Premier Colin Barnett said there was nothing extraordinary about the insurance process but admitted he hadn't seen the documents.

"Mr Buswell does not own the vehicle. It is a government-owned vehicle owned through the department of premier and cabinet so they essentially handle the insurance side of it," Mr Barnett said.

"Whether there is ultimately a claim on Troy Buswell himself, that will be determined by the insurers.

"There's nothing untoward other than the incident itself but in terms of the claim and the repairs to the vehicle, that's normal practice."

Mr Buswell was fined $3100 and disqualified from driving for one year after he admitted to 11 traffic offences. He did not face drink-driving charges and was not breathalysed on the night.

RiskCover has asked for more information about the accident.