Criminologist Paul Wilson played a game of hide and seek with a young girl while he was naked in his bedroom, a Brisbane court has heard.

Wilson has pleaded not guilty to four counts of indecent treatment of a girl under the age of 12 in the mid 1970s.

In the opening day of the District Court trial, crown prosecutor Phil McCarthy said the jury would hear evidence suggesting Wilson asked the girl to stroke his genitals while she visited his home in Indooroopilly.

Wilson, now in his 70s, was married at the time and had a daughter with whom the victim's siblings used to play.

It is alleged the first time he encouraged the girl into his bedroom, she found a life-size naked poster of Wilson on the back of a door.

The court was told Wilson often enticed her to undress and on one occasion placed his penis against her thigh.

Wilson later tapped her vagina with his penis, the court heard.

The crown will also allege that the defendant digitally penetrated the girl during one of her play visits.

Later in the proceedings, the court was closed so the girl - now a woman - could testify.

Wilson is the former head of criminology at Bond University on the Gold Coast.

A new jury was empanelled this morning after the first group of jurors selected for the trial was discharged.

A member of that jury yesterday informed the judge he was not sure he could remain impartial throughout the trial.