The political future of WA Treasurer and Transport Minister Troy Buswell is in doubt this morning amid reports he was involved in a car crash before taking personal leave.

The Treasurer has been on personal leave for more than two weeks despite a heavy workload which includes handing down a state budget in two months.

His ministerial car was involved in a crash outside his home on Roberts Road in Subiaco in the early hours of Sunday, February 23.

Police say they received a call early that morning regarding a traffic matter on Roberts Road in Subiaco on that date.

A police traffic enforcement vehicle attended the location shortly afterwards.

The vehicle remains in the carport with its front bumper on the driveway.

Last week, Premier Colin Barnett announced Mr Buswell had taken leave due to health-related reasons.

At the time, Mr Barnett told the ABC he had been aware of Mr Buswell's "condition" for "some time" and said it is likely the Treasurer would provide an explanation when he returns.

The Premier is expected to make a statement later this morning and reveal further details.

Controversial career

Mr Buswell's career in politics has been marred by indiscretions.

He was previously forced to resign as the leader of the WA Liberal Party in 2008 after admitting he sniffed the chair of a female staff member and snapped a Labor staffer's bra.

He was then appointed to the front bench under new leader Colin Barnett.

The damaged front bumper of Treasurer Troy Buswell's car. ( ABC News: Graeme Powell )

He again stepped down from the front bench as WA Treasurer in 2010, after allegations surfaced that he used public funds to arrange meetings with lover and then Greens MP Adele Carles.

Mr Buswell and Ms Carles were both cleared of misusing ministerial entitlements in June 2010 and Mr Buswell returned to the front bench in December.

He was advised by the Premier when appointed Treasurer that he was on his final warning.

Last year, the Treasurer denied trying to hide a controversial budget decision involving the WA Insurance Commission, which allowed the Government to take up 65 per cent of the commission's profits.

Mr Buswell has recently been criticised by the State Opposition for using double standards regarding leave targets.

Since Mr Buswell directed government agencies to cap leave liabilities in 2012, the levels have instead increased by 13 per cent to around $375 million.

Shadow Treasurer Ben Wyatt said last month the situation was hypocritical.

"What this is, is more financial crisis, more financial disarray and a government that simply has no ability to deliver on the strong rhetoric that it likes to spout," he said.

The Premier has assumed temporary responsibility of the Treasury portfolio, and will be assisted with the budget process by the Finance Minister Mike Nahan.