The death of Ms Caldwell in April 2005 was one of Scotland’s longest running unsolved murders.

The news of Packer’s appeal came as Emma’s mother Margaret Caldwell met Scotland’s chief constable as the family continued their campaign for a public inquiry into the police investigation into her death.

Officers initially arrested four Turkish men in connection with the murder but they were released a year later when the case against them collapsed.

Emma’s family believe that a “toxic culture of misogyny and corruption” within what was then Strathclyde Police meant that women and girls who came forward to speak up against Packer at the time were ignored and he was dismissed as a suspect.

They say this allowed Packer to continue raping other women after murdering Emma.

Chief Constable Jo Farrell apologised to Mrs Caldwell and her family for the policing failures, and backed their call for a full inquiry.

She said: “It is important that Emma’s family and the public get answers to the many questions they have.

“I therefore support the family’s calls for a public inquiry. I absolutely commit that Police Scotland will fully participate in any further proceedings.

“We have reflected and learned from the initial investigation and subsequent re-investigation.

“Significant changes have been made to improve organisational culture and response, particularly in respect of investigative structures, victim care and processes to these types of crimes.”

Margaret Caldwell met First Minister Humza Yousaf to discuss the case on Tuesday and will meet Scotland’s top law officer, Lord Advocate Dorothy Bain, on Thursday.

Mr Yousaf has previously indicated that he would be open to a public inquiry being held, with the Scottish government due to make a statement in the Holyrood chamber on Thursday afternoon.

Packer will not be released pending his appeal, which will take place at a later date.