A former Queensland state cricketer jailed for child sex offences has been identified as the victim of a brutal attack at Canberra's prison.

Convicted paedophile Ian Harold King, 69, was bashed in the face when he was mixing with other inmates while receiving his daily medications on Sunday morning.

King was taken to the Canberra Hospital and underwent emergency surgery.

Child sex offenders like King are routinely separated and placed in high-protection cells for their own safety.

Authorities would not say why King was able to mix with his attacker, but Corrections Minister Shane Rattenbury says the small size of Canberra's jail makes it a challenge to adequately separate different classes of prisoner.

"Prisons are a difficult and challenging environment where people are perhaps prone to use violence to resolve disputes," he said.

The police are investigating Sunday's assault, and the Government will conduct a review.