A Scottish teenager who was allegedly caught with £1.5 million worth of cocaine in Peru faces a jail sentence of up to 25 years if she is convicted.

Melissa Reid, 19, and her friend Michaella McCollum Connolly, 20, from Northern Ireland, are being held in custody after trying to book a flight from Lima to Madrid.

They were allegedly carrying 11 kilos (24lb) of the drug hidden among food in their luggage and, according to reports locally, were caught by sniffer dogs because of their nervous attitude at check-in.

Peru imposes sentences of between 15 and 25 years for those convicted of smuggling more than 10 kilos.

Ms Reid, of Lenzie, East Dunbartonshire, who had been living on Ibiza since June, had not told her parents she was travelling to South America. She was attempting to catch a flight to Palma, via the Spanish capital when the arrests happened.

Her father William Reid was said to be shocked to find out his daughter was in Lima.

He reportedly said: "We don't know anything. We haven't been told anything.

"We don't have any new information. We are not in a position to elaborate.

"We're in the position where we are just trying to come to terms with it."

The Foreign Office said it was providing consular services to both Ms Reid and her family.

Ms Connolly, of Belfast, had been at the centre of a Europe-wide missing persons search until news of her arrest broke at the weekend.

The 20-year-old photography student was looking for work as a dancer and hostess in Ibiza's resort of Sant Antoni. When she lost touch with family they launched an internet campaign to find her.

Both women are now facing potentially very serious sentences if found guilty, according to Ireland's recently retired consul general in Lima. Michael Russell said Ms Reid and Ms Connolly could face up to a quarter of a century behind bars if convicted, thanks to the sheer scale of the alleged haul.

If they are convicted of possession rather than trafficking they can expected to get a reduced sentence of up to seven years, he said. Inmates are entitled to apply for parole in Peru after serving one-third of their time.

International organisations have previously expressed concerns about Peruvian jails. At least one is said to be too dangerous for consular officials to visit.

Mr Russell said prisons in the country were "pretty dour and pretty horrible". He added: "It's all a matter of money, quite frankly. You have to buy your space, you have to buy your food. If you don't have money you suffer quite a lot."

Mr Russell retired at the end of last month, and Ireland has not replaced its honorary consul general in the Peruvian capital. "It's being handled by the British embassy," he said.

In Peru, the state will appoint a solicitor if the defendant does not have one.

Mr Russell said they are "not always the best" lawyers.

Another potential hurdle is the competence of state-appointed translators, whose declaration would be crucial to the severity of the sentencing, he added.

London-based charity Prisoners Abroad has warned previously the number of UK nationals caught up in Peruvian jails has grown as the country begins to succeed Columbia as Europe's biggest source of cocaine.

The charity said: "Peru has now arguably displaced Colombia as the world's top cocaine producer. This has had a direct impact on the lives of hundreds, if not thousands, of people and has translated into a drastic increase in arrests for drug-related offences."