Scot Melissa Reid and Michaella McCollum Connolly said they were forced at gunpoint to make the journey from the Spanish holiday island of Ibiza - where they had been working in bars - after being befriended by a man from London.
They said they were shadowed by gang members throughout the journey and warned that if they did not pick up the drugs in Peru and bring them back to Spain their families would be killed.
The claims come after a the head of the Ibiza police unit responsible for countering organised crime said he did not believe they were acting under duress.
Human rights lawyer Peter Madden, representing 20-year-old Michaella McCollum, said she claims to have been threatened by a gang of as many as 14 armed men.
"She was in fact kidnapped, held at gunpoint and forced by threat to obtain and carry drugs back to Lima," said Mr Madden from the Belfast firm Madden and Finucane.
"She wasn't offered any money. She was threatened and held. She is now prepared and ready to give full details to the police who are in a questioning process."
Ms McCollum, a former nightclub host, and co-accused Melissa Reid, 20, were arrested as they tried to board a flight to Madrid on August 6.
Peruvian authorities say they found more than £1.5 million-worth of cocaine stashed in food products in their luggage.
Mr Madden said his client would be protesting her innocence.
"I think there is hope but it depends very much on the prosecuting authorities here as to whether or not they're going to do this in a fair way, because the process here seems to be that once you're charged there's no bail for these type of offences and she will have to go to trial," he said.
Meanwhile in an interview with the Irish Daily Mail newspaper, Ms McCollum told of the moment she realised she was being used as a drugs mule.
"That's when we realised they were drugs," she told the newspaper. "We didn't know before that what they wanted us to take: guns, money, drugs. There was no option. We just wanted to get it over and done with and not be killed."
She spoke of her relief when they were stopped by police at Lima airport.
"We felt relieved too that it was over," she said.
However, the head of the Ibiza police unit responsible for countering organised crime, first sergeant Alberto Arian Barilla, said he did not believe they were acting under duress.
"In my experience I don't think these two girls were forced to do this because - particularly when you go to South America - you need to pass several controls," he told the BBC Radio 4 Today programme.
"The first thing you do is go to the passport control and say 'Listen, this is what is happening to me'. The policeman will react so I don't think they were forced."
Ms Reid, from Lenzie, East Dunbartonshire, and Ms McCollum Connolly from Dungannon, Co Tyrone in Northern Ireland, were arrested last week as they attempted to leave the Peruvian capital, Lima, on a flight to Spain.
They are suspected by police of trying to leave the country with 11 kilos of cocaine in their luggage worth £1.5 million.
They may be held pre-charge for up to 30 days and could then spend up to three years in prison before a trial.