Former West Australian treasurer Troy Buswell has been charged with 11 traffic offences after allegedly cutting a trail of destruction through his home suburb when driving home from a wedding in February.

Police charged Buswell by summons following an investigation into a series of crashes in the Perth suburb of Subiaco in the early hours of February 23.

Buswell attended a wedding at Kings Park the night of February 22.

He took several weeks' leave from Parliament following the alleged incident and eventually resigned his ministerial portfolios after suffering a breakdown.

Police will allege Buswell drove in a careless manner and as a result of his driving, crashed into cars parked on Olive Street and Barker Road.

Four vehicles and a telegraph pole were damaged.

He has been charged with three counts of failing to stop at a traffic crash, four counts of failing to report a traffic crash and four counts of careless driving.

Premier Colin Barnett said he would not be commenting on the charges.

"I was made aware via police media release that Troy Buswell has been charged with various traffic offences," Mr Barnett said in a statement on Tuesday.

"The matter is being handled by WA Police and is now before the courts and I don’t intend to make further comment."

Opposition: 'Who knew what and when?'

The Opposition has called for an inquiry into who knew what about the incidents.

Labor leader Mark McGowan stopped short of calling for Buswell to resign as the Member for Vasse, but said some senior staff knew about the incident within hours but did not report it.

"There's still very serious questions to be answered by the Premier's office, the Premier's staff, about who knew what and when about these allegations," he said.

"I think the public has an expectation that the Government will come clean on all of those issues.

"The only reason these allegations have come to light is because a single witness came forward, otherwise we may never have heard about these issues."

Lawyer Johnson Kitto told ABC Local Radio that the magistrate would only deal with the charges in front of the court.

"If the charges are, for instance, careless driving, fail to stop, fail to report, then they are the charges and the accused person is required to plead guilty or not guilty, and they're not required to tell anyone whether they were drinking or not by the time the matter gets to court."

"Now, I understand in this particular case, a motorist has been charged in relation to an offence that was allegedly committed some days earlier so he will not be required to state whether he had been drinking."

Mr Kitto says he cannot comment on particular cases but if there is a guilty plea the matter will be dealt with on the day, otherwise it could go further.

"If the matter went to a hearing, it could well be the subject of cross-examination as to whether the motorist had been drinking, or was using drugs or was in a hurry, or was speeding or was upset or anything like that," he said.

"All of those questions are quite appropriate questions that could be put to an accused under cross-examination."

Troy Buswell's personal leave extended

Buswell's personal leave was recently extended by the Government until April 10, the day before the three-week Easter break, meaning he is not expected to return to work before May.

Under WA law, MPs convicted of offences for which the penalty is a jail term of more than five years are disqualified from Parliament.

The maximum penalty for the driving offences Buswell has been charged with is a fine.

Police have said independent legal advice was sought from the State Solicitor’s Office before the charges were laid.

Buswell is due to appear in Perth Magistrates Court on April 29.