Body locked inside Perth Hungry Jacks toilet cubicle ‘for up to three days’ before being found

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

Police were called to the Hungry Jacks on Wanneroo Road in Balga at 9am on Monday morning following the discovery of a man’s body.

It is believed the man had been inside the locked toilet cubicle for three days after entering on Friday night.

The restaurant was closed by workers at 10pm on Sunday, presumably with the man's body in situ.

Staff told 9NEWS the particular cubicle where the body was found had been out of order.

A spokeswoman for WA Police would not confirm whether a staff member had alerted police to the body.

“There are no suspicious circumstances surrounding the death, so we’ll prepare a report for the coroner,” the spokeswoman said.

There are reports his death might have been caused by a drug overdose.

Stirling City Council health compliance officers 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.