Former AFL star Ben Cousins has been caught by police inside the secure facility of Perth's Special Air Service Regiment.

The 36-year-old was found inside the SAS Campbell Barracks in Swanbourne on Saturday night, but it is not known why he was there.

Cousins was taken to hospital, where he is believed to have undergone assessment at a mental health ward.

He has since left the hospital.

Police were still investigating whether to charge Cousins with an offence.

The former West Coast Eagles captain is due to appear in court on April 8 on reckless driving charges stemming from a police pursuit in Perth last week.

Police allege the former midfielder was driving erratically in the southern Perth suburb of Bicton about 10:30pm on Wednesday when he failed to stop for officers.

He was arrested after a short chase that ended at the intersection of Gill and Solomon streets in the nearby suburb of Mosman Park.

Cousins was charged with reckless driving, failing to provide a breath test and failing to stop.

Cousins has had a long and public battle with drug addiction and abuse.

During his 11 years with West Coast, he won several of the league's highest individual awards, including a Brownlow Medal.

Cousins had his contract terminated by the Eagles in October 2007 and a month later was banned from the AFL one year for bringing the game into disrepute.

He was cleared to return to football in 2009 and was drafted by Richmond Football Club, before ending his career at the end of 2010.