The McGowan Government is dealing with its first true crisis.

Mounting evidence casting doubt about the storied past of one of its MPs may have significant repercussions for the new Labor Government.

Darling Range MP Barry Urban has admitted a medal he claimed he was awarded for overseas policing service had actually been purchased online.

The revelation on the weekend angered many military veterans, including within Mr Urban's own party, and cast doubt over other aspects of the first-term MP's past.

It became clear that Mr Urban also had not told the truth about the medal when questioned, both by journalists and his own boss.

Then doubts were raised about the validity of Mr Urban's university degree, when the British institution he claimed to have attended revealed it had no record of him.

WA Labor MP Barry Urban wearing his controversial medal. ( Facebook: Barry Urban MLA )

Labor is now investigating all the details of Mr Urban's past and inquiries are being made about whether any false claims were made in Mr Urban's application to join WA Police, prior to him entering Parliament.

Barry Urban's claims all now in doubt

Such is the level of doubt that now exists, the Premier would not even guarantee Mr Urban actually did serve in a peacekeeping and war crimes investigation role in Bosnia in the 1990s during his time as a police officer, as he has repeatedly stated.

"We are seeking that information currently," Mr McGowan said.

The Premier said yesterday that he had "full confidence" in Mr Urban, but his response 24 hours later was qualified.

"On the basis of what Mr Urban has told me, he does [have my full confidence]," Mr McGowan said.

The Premier will now demand Mr Urban offer a full explanation of his past to State Parliament.

"I think that will be a good thing for him to do, a good thing for the Parliament to hear and good for the people of his electorate," Mr McGowan said.

Mr Urban has stayed away from State Parliament since the medal revelations first surfaced, with Mr McGowan saying the MP was in "considerable distress" and receiving medical attention.

Since the release of a statement on Saturday in which he "apologise[d] profusely" over the medal issue, Mr Urban has made no further comment.

But in his absence, Mr McGowan has had to respond to scores of media questions about Mr Urban, even though he is quite clearly no longer sure of the answers himself.

Public's trust tested

Mr McGowan and Labor have also been left to deal with the broader implications.

The chequered medal (left) that WA Labor MP Barry Urban bought online. ( Facebook: Barry Urban MLA )

Labor will inevitably be wondering how its pre-election candidate screening process failed to pick up any concerns.

Politically, the issue is at the very least a distraction for the Government, and potentially something much more damaging.

The prospect of more serious fallout is now difficult to discount, with scenarios that lead to Mr Urban being forced out of the party — or even quitting Parliament — clearly possible.

The hypothetical loss of a seat would mean little practically, given Labor's huge Lower House majority, but it is nevertheless a situation the party would be desperate to avoid.

Regardless, if further inconsistencies emerge, Mr McGowan will have some difficult decisions to make.

"I think we need to get to the bottom of his record and let him make an explanation to the Parliament before any such decisions are made," the Premier said.

However it plays out in the end, Labor's greatest worry will be that Mr Urban's false statements sow a seed of public distrust in the McGowan Government that may prove difficult to kill off.