Police are trying to identify a man they believe installed hidden cameras in public toilets at a rest stop south of Perth.

A cleaner found two homemade devices fixed inside two female toilet cubicles at rest bays on Forrest Highway in Waroona on Sunday.

Detective Senior Sergeant Jon Munday says police have video footage of a man they would like to speak to about the cameras.

"What we've been able to identify from looking at the footage is that the person that we have an image of is the most likely person that we believe would be able to assist us [in locating] whoever's set these devices up," he said.

Police have asked anyone who can identify the man is asked to call Crime Stoppers on 1800 33 000.