POLICE are trying to determine how a man’s body could have gone unnoticed for nearly three days in the toilet of a Hungry Jack’s restaurant.

Officers were called after the body was discovered in a locked cubicle at the Hungry Jack’s on Wanneroo Road in Westminster, in Perth’s north, on Monday morning.

Police believe the man might have entered the toilet on Friday night and his body remained in the toilet all of Saturday, when the store was open for 24 hours, and Sunday.

The restaurant was closed by workers at 10pm on Sunday before the body was discovered by employees at about 9am on Monday.

Firefighters were called at about 10am to forced open the cubicle, which had been locked.

If the man’s body had been there since Friday, that would indicate the cubicle wasn’t checked or cleaned on Friday evening, all of Saturday and Sunday.

A WA Police spokeswoman said the man’s death was not being treated as suspicious. It’s believed the man may have died of a heroin overdose.

However police will investigate why it took so long for the man’s body to be found, and they will prepare a report for the coroner.

Hungry Jack’s refused to answer questions about cleaning arrangements at the restaurant and released a statement through a PR agency saying it was co-operating with all relevant authorities regarding the matter.

“Our thoughts are with all concerned,” it said.

Council health compliance officers from the City of Stirling were also investigating the death to make sure there was no public risk.

That included looking at whether health or sanitary issues needed to be addressed, a spokeswoman said.