Trio charged over detention centre assault

Three men have been charged over the alleged assault of a man at an immigration detention centre, northeast of Perth.

The 41-year-old man was rushed from Yongah Hill Detention Centre to Northam Hospital with face and head injuries after he was assaulted at midday on March 5.

After being assessed at Northam, the man was taken to Royal Perth Hospital in a critical condition.

Yongah Hill was set up to house single male asylum seekers in 2012, but now contains a mix of asylum seekers and convicted criminals, including visa overstayers.

AAP understands the victim was a 501 detainee - someone who has had their visa cancelled under section 501 of the Migration Act - and not an asylum seeker.

Police said three men aged 42, 40 and 26 years had been charged with assault occasioning bodily harm in circumstances of aggravation.

They are scheduled to appear in Perth Magistrates Court on March 23.

The Department of Immigration and Border Protection said at the time of the alleged attack that service provider Serco would provide a full report on the incident.