ONE of Scotland's toughest prisons is on alert after killer Alexander Pacteau received a number of threats against him.

The threats have come from other prisoners at Barlinnie in Glasgow, where the former private schoolboy is currently being remanded in custody. Some are understood to be death threats.

At the High Court in Glasgow on Tuesday, Pacteau admitted murdering Irish student Karen Buckley whose body was found on an East Dunbartonshire farm four days after she went missing from the Sanctuary nightclub in Glasgow.

The 21-year-old killer is being held in a part of the prison reserved for those on remand who are awaiting sentence, however prison officers are known to have been warned about the threats that have been directed at Pacteau as a result of the case.

A prison source confirmed prison officers were on alert over the former Kelvinside Academy student's safety because of the threats.

He added: "Yes, there have been threats.

"It will be fair to say that where there is someone involved in a high profile case such as this, then special attention is paid to ensure their safety.

"People watch TV and read newspapers and a case with this kind of profile it is incumbent on us to take whatever steps we require to do to ensure the safety of the individual."

Pacteau, who faces a mandatory life term when he is sentenced on September 8, would have limited contact with other prisoners at mealtimes as food would be taken into cells, the source said.

"There's a servery that people will get their food from, but they (prisoners) would normally go into their cell to eat it," he added.

Pacteau admitted repeatedly hitting Ms Buckley with a spanner and strangling her in his car in April.

He then hid the body of the 24-year-old from Cork in his Glasgow flat where he tried to dispose of it with caustic soda before dumping the remains at High Craigton Farm, near Milngavie, East Dunbartonshire.

After sentence was deferred Ms Buckley's father said Pacteau was "evil" and should spend the rest of his life in prison.

Glasgow Caledonian University, where Miss Buckley was studying occupational therapy, has offered the family continued assistance if needed.

A university spokeswoman said: "Our thoughts are with Karen's parents, family and friends at this difficult time and we are continuing to offer them our support."

After his guilty plea it emerged Pacteau had a previous conviction for printing counterfeit money and that he also stood trial at the High Court in Paisley in 2013 accused of attempting to rape a woman in Baliol Lane, Glasgow. He was found not guilty of the charge.

Pacteau met Miss Buckley outside The Sanctuary in the early hours of the morning on April 12.

CCTV footage captured them walking along Dumbarton Road and Pacteau then drove with her in his car to nearby Kelvin Way.

The car was parked on the street for 12 minutes, during which time Pacteau, who describes himself as a 'self-employed sales consultant', attacked and murdered her by grabbing her neck and delivering 12 or 13 blows with the spanner.

Miss Buckley suffered injuries to her arm as she tried to defend herself.

Her family were in court as Lord Advocate Frank Mulholland QC, prosecuting, told how Pacteau attempted to dispose of her body.

He embarked on a journey to various stores to buy quantities of caustic soda before placing her body in the bath at his flat after making sure his flatmate was out for the day.

Pacteau made trips to High Craigton Farm where he burned a mattress, clothes and cleaning materials before buying a barrel, placing Miss Buckley's body inside and locking it in a storage unit he had rented.