Police have scaled up the search for a swimmer who was spotted in distress off Trigg Beach on Tuesday evening.

On Wednesday, the Mounted Police joined the Police Air Wing, Marine Rescue WA and Surf Life Saving crews as they continued searching for a male who was seen in distress about 100 metres offshore about 5.15pm the night before.

Police say the swimmer was not seen getting out of the water.

The man had still not been located by 4pm Wednesday and police are still trying to confirm his identity.

The public is being asked to urgently report any information about the swimmer.

An official missing person has not been reported in relation to the incident, police said.

Police would like to hear from anyone who may have been in distress in the water on Tuesday afternoon at Trigg Beach and self-rescued.

Anyone who witnessed the incident or who has not heard from a family member or friend who went to Trigg Beach on Tuesday, is asked to contact police immediately on 131 444.

It’s expected search efforts will continue throughout the afternoon on Wednesday and likely into the night.