Michael Alan Gillard ... will appeal his conviction to the High Court.

Michael Alan Gillard ... is appealing his conviction to the High Court. Photo: Marina Neil

A Canberra man who sexually abused a teenage girl in front of her sister has taken the fight against his conviction and punishment to the highest court in the country.

Michael Alan Gillard, 60, was found guilty of eight offences against the elder sister in 2011 and was sentenced to nine years and nine months in prison.

He had been looking after the girls for short periods of time at his Canberra home.

Gillard abused the girl when she was under the age of consent, 16, and then again after her 16th birthday.

The crime after she was 16, involving oral sex, was said to have occurred in front of the girl’s sister.

The sister gave evidence that Gillard had bragged that the victim and he had a ‘‘special bond’’, because they both did whatever the other told them to do.

The girl said Gillard had turned to her sister and said:

‘‘Come... on your knees. You know what to do.’’

But Gillard disputed that version of events, saying the girl had consented to the sexual act after she was 16.

He said the pair had begun kissing and touching each other, and he had said to her ‘‘it would be nice if you went down’’.

The Crown argued at Gillard’s trial that even if the girl had consented, that consent was negated because the older man had abused his position of authority or trust.

But Gillard’s lawyers have argued the trial judge, former chief justice Terence Higgins, gave wrong advice on the issue of consent to the jury when directing them at the end of the case.

They took that fight to the ACT Court of Appeal last year, but failed to convince the full bench that former chief justice Higgins had made the error.

But in November last year Gillard won  the right to take the case to the High Court of Australia.

The hearing took place on Thursday, with Gillard appealing convictions and sentences on four charges before five of the seven High Court justices. Gillard’s counsel said that if the appeal succeeded for all four offences, they should be quashed and a re-trial ordered. If the appellant was successful on just one of the counts, he argued re-sentencing should occur to adjust Gillard’s non-parole period.

The Crown is arguing  no error was made by the ACT Court of Appeal.

The High Court reserved its decision and will hand down judgment at a later date.