Matthew James Massey, 37, received stitches in his leg when two detainees attacked him with a shiv – a makeshift knife – at the Alexander Maconochie Centre on Friday morning.

Fairfax Media understands one of theassailants is serving a 10-year sentence for a spate of knifepoint robberies in 2009.

But police say charges over the assault are unlikely after Massey refused to co-operate with investigators.

A Justice and Community Safety Directorate statement confirmed an inmate was injured after a “minor” incident. “ACT Corrective Services staff dealt with the matter appropriately, ACT Policing were contacted and have concluded their investigation,” the statement said.

“An ambulance was not required and treatment was provided on-site.”

Massey, who has spent most of his adult life behind bars, has a reputation in the underworld for being a hard man who demands respect from both prisoners and guards. He has more than 50convictions for crimes ranging from armed robbery to escaping custody.

A string of armed robberies in 1994 earned him five years behind bars, but despite vowing to live a ‘‘pro-social life’’, he continued to offend on release and spent a further seven years locked up.

In 2011, he was jailed for four years for kidnapping and unlawful confinement and was then caught in possession of a stolen bike and a bag of identity cards while on conditional release in July last year.

The convicted armed robber was locked up again in March after he allegedly breached his release obligations on a number of occasions.

The ACT Magistrates Court heard Massey had failed to report, not attended alcohol and drug treatment, and refused to provide urine for analysis on four occasions.

The bricklayer and painter blamed a cat allergy for not attending one appointment and suspected broken ribs for not providing a urine sample on another occasion.