Andrew Miller, also known as Amy George, lured the young victim into his car in February while dressed as a woman.

The 53-year-old, who was addressed as a male by the court, appeared via video link to plead guilty at the High Court in Edinburgh on Thursday.

First Minister Humza Yousaf told Sky News he cannot say whether Miller will be detained in a women's jail after being sentenced.

"This is a gut-wrenching case - heart-breaking. I cannot think of the trauma the victim and the family, in fact the community, are going through.

"I can confirm, of course, that Andrew Miller is being held in a male prison. But I cannot say which one and I cannot go into the details."

Asked if he would remain in a male prison, Mr Yousaf replied: "This is a live case. The sentencing is still to happen, so I can't comment any further."

The court was told the child was walking home when the sex offender, who was a stranger, offered her a lift in his vehicle because she "looked freezing".

Miller, who is currently transitioning, confined his victim inside his bedroom before repeatedly sexually assaulting her over the next 27 hours at his home.

The prosecution described how the child only managed to escape and call 999 when Miller fell asleep.

Police described her fear as "palpable" when she was rescued from Miller's home.

The age of the victim and location of the crimes cannot be revealed to protect the victim's identity.

The local butcher shop he once owned was boarded up by detectives at the time.

'Every parent's worst nightmare'

Miller pleaded guilty to four charges - abduction, sexual assault, watching pornography in the presence of the child, and possessing 242 indecent images of children.

The judge, Lord Arthurson, told Miller his offences represented "abhorrent crimes" of the utmost "deviance and depravity" and were "the realisation of every parent's worst nightmare".

Miller was remanded in custody and will be sentenced on 15 August.

At the time of his arrest, Miller was wearing a bra, women's underwear, tights and one silicone breast - the other had become dislodged during a struggle.

Detective Chief Inspector Bryan Burns said: "Our thoughts today are with the victim and her family who have shown incredible courage and strength throughout this ordeal.

"This was a significant investigation and I would like to thank all those involved for their professionalism and commitment during what was an extremely challenging inquiry.

"Andrew Miller has pled guilty to serious offending and will now face the consequences of his actions."

Trans prisoners in Scotland

Earlier this year, Scotland paused the movement of any transgender prisoner while it carried out an "urgent" review of the rules.

It followed a public outcry after Isla Bryson, a transgender double rapist, was initially imprisoned in an all-female prison before being removed to a jail with male inmates.

Bryson, a serial sex offender who attacked vulnerable women when she was known as Adam Graham, decided to transition while awaiting trial, which provoked outrage among campaigners.

Scotland's gender reforms

The Scottish parliament's Gender Recognition Reform (Scotland) Bill was passed in Holyrood last year, but the government in Westminster announced it was blocking the bill from Royal Assent and becoming law - the first time the power has been used since devolution nearly 25 years ago.

Critics have raised concerns predatory men could obtain a gender recognition certificate in Scotland in order to gain access to single-sex spaces and place women in jeopardy, and those spaces would have to adopt different policies.

Those in favour of the bill argue it would introduce a simpler and fairer way for trans men and women to be legally recognised as who they are.