A solicitor for Michaella McCollum, the Tyrone woman suspected of drug-smuggling in Peru, said she has not been charged but could be in Peru a "long time".
Solicitor Peter Madden has flown out of Belfast and is due to arrive in Peru at 6am local time on Friday.
Ms McCollum, 20, was arrested trying to fly to Madrid a week ago, along with Melissa Reid, 19, from Scotland.
It is alleged police found £1.5m worth of cocaine in their luggage.
The two women had been due to appear in court on Wednesday, however the case was delayed.
Mr Madden said he had spoken to Ms McCollum on the phone.
"She said she did nothing wrong and is innocent," he said.
Asked about reports that his client had been forced at gunpoint to go to South America, he said it "chimed" with what she told him, but he had not spoken to her yet in detail.
Mr Madden said Ms McCollum sounded well on the phone but was in a "difficult position" for a 20-year-old woman so far away from home.
He said he hoped to obtain a local legal team in Lima to represent the Dungannon woman in court.
In a statement issued through their solicitors, the McCollum family said Michaella denied involvement in any criminal offence.
The two women were stopped on 6 August as they tried to pass through the Air Europa counter at Jorge Chavez airport in Lima. They face lengthy prison sentences if found guilty.
Ms McCollum had been studying photography in Belfast, but had gone to the Ibizan town of San Antonio in June, to look for work as a dancer or a nightclub hostess.
After hearing nothing from her for 12 days, her family appealed on social media for any information on her whereabouts.
Both women have been visited by officials from the British embassy.
Ms McCollum holds an Irish passport and the Irish Department of Foreign Affairs has also confirmed it is providing consular assistance to Ms McCollum's family.