Ezra Mam of the Broncos during the NRL Round 18 match [Source: AAP Image/Jason O'Brien]

Brisbane star Ezra Mam is facing an NRL integrity unit investigation after allegedly failing an initial roadside drug test following a head-on car crash.

Mam was accompanied by police at hospital on Friday night, after he was allegedly involved in an accident in the Brisbane suburb of Bardon.

He had scans on his head following a bump, but was later released and the injury is not believed to be serious.

Mam underwent initial roadside drug and alcohol tests, to which AAP has been told he returned a positive result for drugs.

The 21-year-old was then ordered to undertake a second drug test using blood samples, with police awaiting the results of those.

“Police are investigating following a two-vehicle traffic crash at Bardon last night, October 18,” police said in a statement.

“Initial investigations indicate at approximately 5.20pm, a Ford Ranger utility was travelling north-east along Simpsons Road when it stuck a Toyota Camry, travelling in the opposite direction, near the intersection of The Drive.

“Initial roadside drug testing was conducted on the driver of the utility, a 21-year-old Ipswich man; however, police are awaiting further results.

“No one was seriously injured, and investigations are continuing.

“No one is in custody.”

The Broncos informed the NRL’s integrity unit immediately on Friday night, and are still attempting to gain further clarity around the drug tests.

The club’s welfare officers attended the scene of the crash, and have been in constant communication with Mam.

It is the second drama to beset Mam since the end of Brisbane’s horror season, after the NRL looked into an interaction between he, Reece Walsh and a fan in Bali last month.

Roadside drug tests have also become a constant issue for the NRL this season.

Cronulla playmaker Braydon Trindall tested positive to driving with drugs and alcohol in his system in May, and missed five games of football.

Canterbury flyer Josh Addo-Carr also missed the Bulldogs’ elimination-final loss to Manly as the result of a positive roadside drug test.

Addo-Carr remains on the outer at Belmore following the test, and is expected to be released by the club with an NRL-imposed suspension still hanging over his head.