Scottish authorities have less than two months to extradite a former Catholic monk accused of child abuse at the scandal-hit Fort Augustus Abbey School.
Fr Denis "Chrysostom" Alexander, 83, recently failed in a challenge to the Australian government's decision to allow him to face trial in Scotland.
Fr Alexander denies the allegations and is being held on remand in Sydney.
But he could be released if the Crown Office does not act quickly enough on the surrender warrant.
The allegations against Fr Alexander were first revealed by the BBC in 2013.
He is accused of engaging in "acts of physical and sexual abuse" against six complainants, aged between 11 and 15, while he was a teacher at the prestigious Highlands boarding school between 1970 and 1976.
The Crown Office launched extradition proceedings in December 2016, but since then he has contested the move on health grounds.
Fr Alexander was arrested in Sydney almost three years ago and has been in custody ever since.
Last month the Federal Court of Australia dismissed his case for a judicial review of the attorney general's decision to extradite him to Scotland.
Fr Alexander had until 5 December to lodge an appeal against that ruling, but failed to do so.
This means the Crown Office would have until 5 February to execute the surrender warrant.
A spokesman for the attorney general said: "The Federal Court may order the release of a person that is in custody under a surrender warrant more than two months after the day on which the warrant became executable.
"In the event that the Federal Court orders the release of a person that is in custody under a surrender warrant, that person would no longer be eligible for surrender pursuant to that warrant."
The spokesman added that the court could refuse to order the person's release if the surrender had been delayed for "any reasonable cause".
Scotland's Crown Office said the extradition process was "ongoing" but refused to comment further.
Allegations of abuse
One of Fr Alexander's alleged victims, Hugh Kennedy, says he has been consistently dismayed by the delays to the case.
He told the BBC: "It does seem we are drawing nearer to the point where I can face this man in a Scottish court, which is all I've ever wanted since I came forward back in 2013."
Fort Augustus Abbey school, which was run by Catholic Benedictine monks, closed its doors to the public in 1993.
Allegations of decades of child sexual and physical abuse at the exclusive boarding school were finally made public by BBC Scotland in June 2013, in the programme Sins Of Our Fathers.
The programme team spoke to former pupils who claimed they were abused by monks or teaching staff over five decades.
Many of those then reported their allegations to the police, sparking a major inquiry into historical abuse.
The history of the case
July 2013: BBC airs Sins of Our Fathers, revealing decades of sexual and physical abuse at the Fort Augustus Abbey School and Carlkemp preparatory school, and confronts Fr Alexander in Sydney
December 2015: The Crown announces plans to extradite Fr Alexander back to Scotland
January 2017: Fr Alexander is arrested in Sydney and remanded in custody
May 2017: Fr Alexander is found eligible for extradition by an Australian court. He appeals, claiming he is too ill to travel
March 2019: The attorney general of Australia determines that Fr Alexander be surrendered to the UK. Fr Alexander seeks a judicial review
September 2019: The Scottish Child Abuse Inquiry takes evidence about Fort Augustus
November 2019: The Federal Court of Australia dismisses Fr Alexander's application for a judicial review
December 2019: Fr Alexander fails to lodge an appeal against the federal court ruling within the 28-day deadline
5 February 2020: If extradition is not carried out by this date, Fr Alexander will be entitled to apply to the federal court to be released