A 38-YEAR-OLD man who indecently touched two underage teenage girls as they swam at the Milne Bay Aquatic Centre in Toowoomba has been placed on two years probation.

Linthorpe resident Andrew Paul Wenham had been at the aquatic centre on December 19 as had the two girls, aged 14 and 15, who were not known to him, Toowoomba Magistrates Court heard.

The girls had been alternating between the indoor and outdoor pools and had been told that a man had been staring at them, police prosecutor Tim Hutton told the court.

As the girls swam in the outdoor pool, Wenham had repeatedly swum beside them eventually bumping into one girl and apologising.

A little later after Wenham had placed his hand on the 15-year-old girl's thigh and buttocks, she got out of the pool.

After she re-entered the pool, the 38-year-old had approached her from under the water and felt her breasts and wrapped his legs around her leg, prompting the 15-year-old to kick out at him and swim away, Sergeant Hutton said.

The 14-year-old had been floating on her back when she too had been grabbed on her buttocks and breast, Sgt Hutton said.

The girls complained to the pool's lifeguards and security officers who approached Wenham and he left.

When police spoke with Wenham he said he had come into contact with the girls while treading water but believed they were over 16, Sgt Hutton said.

Wenham pleaded guilty to five counts of sexual assault.

His solicitor Chris Lumme said the touching was on the outside of the girls' clothing and that his client hadn't realised their age.

His client had no previous criminal history at all and was very remorseful, he said.

Mr Lumme said his client was studying law and asked that the convictions not be recorded.

Magistrate Bruce Schemioneck ordered no conviction be recorded but placed Wenham on two years probation to include any medical or psychological counselling as deemed necessary.