Michaella McCollum Connolly, who has been arrested on suspicion of drug smuggling, will plead not guilty if she is charged, her lawyer has said.
Speaking as he left Belfast for Lima, Peter Madden said:"She is saying she has done nothing wrong, that she is innocent and that as far as any offences are concerned, if she is charged she will be denying it."
The lawyer said his client "sounded well" considering she was in "a difficult position for a young girl to be in."
Mr Madden, who is due to arrive in Lima tomorrow, did also warn that legal proceedings could be lengthy.
Ms McCollum Connolly as well as Melissa Reid, from Scotland, are accused of attempting to smuggle £1.5million of cocaine out of Peru.
Melissa Reid and Michaela McCollum appeared in court in Lima, but it is unclear whether they have been charged, their lawyer said.
Two women accused of smuggling 12kg of cocaine into Peru could face up to three years in custody and a maximum of 25 years in prison.
A British woman accused of drug trafficking in Peru said she and her friend "were not smuggling for money, we were smuggling for our lives."