Andrew Miller, also known as Amy George, was jailed for 20 years earlier this month and was told he would be supervised for a further eight years upon his release.

He was also placed on the sex offenders' register indefinitely.

Miller, 53, has now launched a legal bid to challenge the length of the jail term.

A spokesperson from the Scottish Courts and Tribunals Service told Sky News: "The court can confirm an appeal against sentence has been lodged."

Former butcher Miller, who identifies as a transgender woman and is said to be in the process of transitioning, lured the young victim into his car after offering to give her a lift home in February this year.

Miller, who was addressed as a male at the High Court in Edinburgh during his sentencing, instead drove the girl to his own house in the Scottish Borders and trapped her in his bedroom.

He then subjected his victim to a series of sexual assaults over the course of the next 27 hours. He also made her watch pornography.

Passing sentence, Lord Arthurson said the crime was "frankly nauseating in its level of depravity and criminal deviance".

The judge described the abduction as "brazen and chilling".

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He added that Miller being dressed as a woman was an aggravating factor as he doubted that the girl would have got into the car if Miller had presented as a man.

Lord Arthurson said: "Your intentions were wicked and predatory, and clearly involved a substantial component of planning."

The court heard the girl was only able to escape after Miller fell asleep on the second night of her ordeal.

She tipped over a glass of water and turned on the bedroom light in an attempt to wake him, but he did not rouse. She then found his landline and raised the alarm. Police arrived at his home within a matter of minutes.

Officers found Miller wearing a bra with silicone breasts, women's underwear and tights.

Defence advocate Victoria Dow told the court that Miller recognised "the horror of his conduct" and felt an "enduring sense of shame".

Miller was also said to have expressed concern over how his behaviour would affect the wider trans community.

Miller pleaded guilty earlier this year to abduction, sexual assault, watching pornography in the presence of a child under the age of 13, and possessing 242 indecent images of children.

Lord Arthurson described the "abhorrent crimes" as the "realisation of every parent's worst nightmare".