A FATHER has been given an 18-month, wholly suspended jail sentence for a single carnal act with his future bride - which resulted in the conception of their daughter - almost 15 years ago.

Brisbane District Court Judge David Reid was last week told what made the couple's union a criminal act was the fact that at the time the future groom was aged 42 and the soon to be mother was his 11-year-old step-daughter.

As revealed by The Courier Mail yesterday, the convicted child sex offender, who is now raising the 14-year-old child who was the fruit of the illegal act, was facing a seven-year stint when he was originally charged by police in 1995.

But he fled interstate after being twice given bail and jailed for several months and was able to elude police for 14 years, 18 months and three-days.

During that time he returned to Brisbane undetected by authorities and married the girl, who by then had turned 18.

They produced a second child - a son - in 2005.

In a sentence imposed this morning that will see the man walk free from court, Judge Reid said: "The facts of this case are most unusual and unlikely to ever be repeated.''

"(Your daughter born as a result of this offence) describes you as awesome dad and (says she) is lucky to have you.''

Judge Reid said as appalling as the facts in the case were there was no evidence the man "groomed'' the girl for sex and that the child had been the sexual aggressor during the one-off encounter.

He said impressionable young girls rightly needed to be protected from predatory older men and that deterrence was an important consideration in cases of this nature.

The man, now aged 58 and who until his recapture in March resided on Brisbane's northside and cannot be named to protect his victim, pleaded guilty on Friday to an act of unlawful carnal knowledge with a girl in his care under 12 during the September 1995 school holidays.

Prosecutor Rebecca Britnell said the man was in a relationship with the child's mother and they produced a son - the girl's half brother about a year before the sexual assault.

Ms Britnell said the man had been asleep naked in his bed when the 11-year-old came into his bedroom, disrobed and they had sex.

The court was told the man told the girl the one-off incident - which he told police was the result of her being the "sexual aggressor" - was wrong and could never happen again.

However, when the girl revealed she was pregnant the pair fled interstate and remained in hiding until her disappearance and her mum's appeal for her safe return became a national media event.

Ms Britnell said the girl, by then 30 weeks pregnant, telephoned her mother shortly after and arrived at Brisbane's Roma Street Travel Centre in April 1996.

She said the girl made a statement to police, the man was charged, bailed by a magistrate, breached it by seeing the girl, was jailed for three months, again bailed and then fled.

The court was told the man remained on the run until police learned of his whereabouts in Brisbane on March 8 this year.

Police contacted the man, gave him 24-hours to sort out his affairs and he surrendered the following day and has been in custody since.

It was also revealed the man returned to Brisbane, rekindled his relationship with the girl and they married, produced a son, separated in 2007 and remain good friends.

The so-called victim, who has supported the man since being charged, today sighed in relief when Judge Reid announced her former husband would not be returning to jail.