A man who manipulated and preyed upon an underage girl to have sex with her repeatedly arranged an abortion for her when she was just 13.

Wade Walter Massey, 41, from Queensland in Australia, entered into a sexual relationship with a 13-year-old girl in 2003, pressuring her to have sex with him multiple times.

She kept Massey’s actions a secret from her family for over a decade before coming forward and finally reporting him to police.

Massey even caused the girl to fall pregnant with his child, and arranged for her to have an abortion at the age of 13, according to the Australian NCA NewsWire.

Crown Prosecutor, Rebecca Marks, told Brisbane District Court that Massey had sex with the girl "almost daily" over the course of their relationship until 2006.

At times, the pair had sex in secret locations like bushland, a shack, and on one occasion a public pool, but had sex at her home on others.

Crown Prosecutor, Rebecca Marks, told Brisbane District Court that Massey had sex with the girl "almost daily"

Massey was 11 years older than the girl at the time, and Marks said he sent the girl text messages saying he couldn't wait and was "going to f*** her" when she was 16.

She quickly fell pregnant with her first child and Massey arranged for the girl to stay at his home until an abortion had been organised.

The court heard the girl spiralled into drug use after the abortion and after their relationship ended, but he continued to see her on and off until 2017.

Ms Marks said: "His behaviour was predatory and manipulative.

"While the complainant engaged in sexual conduct consensually, it must be seen in the context she was at a very young and impressionable stage of her life.

"He preyed on the vulnerability of a young teenage girl."

In 2006, Massey drove the girl to the Gold Coast and prevented her from leaving his car before making inappropriate comments about her shaving her legs.

Massey also accused the girl of "sleeping around" and the relationship began to draw to a close.

A victim impact statement, read by Ms Marks, revealed the girl suffered "long-lasting consequences" that left her with sleep issues, anxiety and depression.

Defence lawyer Janice Crawford said her client had expressed deep regret for the offending and said Massey knew the relationship was wrong but insisted he loved the girl.

The court was told Massey suffered from mental health issues that caused delusions and psychotic episodes and had suffered a brain injury that was causing cognitive decline.

Ms Crawford said: "He has no history of sexual offending apart from this.

"There have been periods in the community where Mr Massey’s mental state and support services have been stable enough."

Massey pleaded guilty charges including maintaining an unlawful relationship with a child, indecent treatment of a child under 16, carnal knowledge of a girl aged 12-16 and deprivation of liberty on Friday, November 20.

Judge Leanne Clare adjourned his sentencing until Monday, November 23.