The boy, who can't be named for legal reasons, was 14 at the time of the alleged offending but is now 18. This week, he faced trial in the Launceston Supreme Court, pleading not guilty to rape.

It was alleged he raped a girl known to him one evening in November 2015.

But the accused's defence counsel Fran McCracken told the court there were too many "inconsistencies" in the alleged victim's account of the night in question.

On Tuesday, the complainant's mother appeared in the witness box, followed by the accused.

The mother said her daughter had gone out into the carport of their unit that night in 2015, to "play with toys". Soon, she discovered her daughter had been gone past her curfew of 5.30pm.

Ms McCracken pointed out that the girl had originally stated that it had been OK for her to be outside until about 10pm, arguing that the complainant had made up the story so as not to get in trouble for staying out late.

According to the mother, her daughter didn't reappear until about 9.45pm.

"She said she went to the bush with [the accused] and he attacked her," the mother said.

The accused said he had been on his way to meet a friend at Mowbray when he saw the alleged victim playing with her friends at a bus-stop and spoke to her.

She is said to have then followed him into nearby bushland.

"We hugged," the accused said of what happened next. "Then we kissed."

They went on to stimulate each other's genitals, the court heard.

Forensic evidence showed that the semen found in a swab taken from the girl's vagina at the time almost certainly matched the DNA of the accused, despite him denying ever putting his penis inside her.

Crown prosecutor Peter Sherriff said the forensic evidence aligned neatly with the girl's allegations.

But the jury took just 90 minutes to reach a not guilty verdict.