The child, who cannot be named, was first made a ward of the state in NSW in 2003, when the Department of Community Services placed him into the care of a couple.

He stayed with them for about eight months, before the couple gave responsibility for his care to his abuser, named in court documents only as "Z".

His lawyers, Ken Cush and Associates, allege in court documents that the transfer was done without lawful authority.

The child was then repeatedly molested for lengthy periods over the next four years, with "Z" forcing anal sex upon him, performing oral sex on him, and fondling his penis.

He was eventually transferred to care in the ACT in 2006, where care and protection services allowed him to remain with "Z" and another person.

Court documents allege the abuse continued in the ACT between May 2006 and January 2007.

The man, represented by solicitor Nicholas Kitchin, has since launched civil action against both the NSW and ACT governments in the ACT Supreme Court.

He alleges that both had information suggesting that "Z" was a paedophile, but failed to adequately investigate or refer it to police.

The governments were said to have taken on a parental responsibility for the child, but breached their duties of care to him in a series of ways.

One of those breaches is described as a failure to undertake "any adequate investigation into the information which the first and second defendants had that "Z" was a paedophile who engaged in grooming behaviours directed toward the plaintiff and who is likely to sexually abuse the plaintiff".

The governments are also alleged to have breached their duties of care by not properly supervising the child, failing to remove him from the care of "Z", failing to report the knowledge it had about him being a paedophile to the police, and failing to take reasonable care of the plaintiff.

"The sexual abuse committed by Z amounted to a failure to adequately supervise the plaintiff," the claim alleges.

The abuse left the boy with psychiatric injury, psychological injury, mental harm, and nervous shock, his lawyers say.

In unrelated court proceedings in the ACT Magistrates Court, the court heard that his abuser has since been convicted and jailed for the crimes.

The boy was paid the maximum amount of compensation available under the victims of crime scheme.

Now an adult, the plaintiff is understood to suffer serious drug, alcohol, and gambling problems. His childhood is believed to have left him deeply scarred. He is currently behind bars at the Alexander Maconochie Centre.

The civil claim was filed in the ACT Supreme Court last year, but his lawyers filed a notice of intention to proceed last month.

Both the ACT and NSW governments have filed notices of intention to respond.