Former West Coast Eagles captain Ben Cousins was assessed at a mental health facility after being caught behind the secure fences of Perth's Special Air Service Regiment.

The Nine Network reported on Sunday night that the ex-AFL star was apprehended at the Campbell Barracks in Swanbourne about 11pm on Saturday.

A Defence spokesperson said they were aware of an incident involving a member of the public and WA Police, which occurred at the entrance to Perth's Campbell Barracks on Saturday evening.



"No Defence personnel were involved in the incident," the spokesperson said.