Michaella McCollum and Melissa Reid may have been part of a 10-person smuggling ring, Peru's former anti-narcotics chief has claimed.
"From our experience, we know that traffickers will usually try and use up to 10 people on a single flight," said ex-drugs czar Ricardo Soberon.
"Some will carry the cocaine in their suitcases, others will swallow it. They are almost always Europeans and put in pairs.
"They will come for a two-week holiday. Everything will be paid for by the traffickers and they will have a nice time in Peru.
"Then they will collect the drugs or they will be brought to them, usually the night before the flight.
"As is well documented, we have certain rogue members of security services here. Corruption continues to be a big problem.
"The deal usually is two or three people will be stopped with the drugs by the police in the airport and the others will get through.
"In the media the next day, it looks fantastic. They say, 'Look we have found the drugs', but in truth more is slipping through."
Mr Soberon also claimed the Dungannon woman should have served her time at a UK prison and said the numbers of tourists involved in drug-smuggling from Peru was at "epidemic levels".
"It is harder to send Peruvians and South Americans to Europe," he said. "We don't have as many tourists going there.
"It is easier to offer young people a free holiday and in some cases €20,000 to move the goods.
"But I don't think they should go to prison here if they are caught. I was involved in Michaella's case before, and I said then she should have been sent home.
"We should not waste our tax money on these people. They should be extradited and banned from Peru. We have more than 200 Spaniards and 50 English people in jail here for smuggling. It is out of control."
Mr Soberon added that McCollum (23), from Tyrone, would probably be home by the end of the year. "She will be home very soon," he said. "Most likely by the end of the year. It would be easy for her to cross the border to Ecuador and fly home from there also before her parole is finished."
McCollum and Reid were arrested at Lima airport in 2013 while trying to board a flight. Initially, both claimed they had been recruited as "mules" by an armed gang while working in bars in Spain and that they were forced to travel to South America.
Later, they accepted the charges and pleaded guilty before a court in the Peruvian capital, Lima, to concealing 11kg of cocaine, worth £1.4m. They were sentenced to six years and eight months in prison but could have faced 15 years.
Under legislation which came into force in 2015, McCollum was released on parole on Thursday.
Meanwhile, veteran broadcaster Gay Byrne criticised the interview with McCollum shown on RTE, saying she should have been pushed harder.
RTE has defended the glossy segment - watched by 550,000 people - amid claims that McCollum was not challenged enough about her crime.
"I think it would have been very easy to push her a bit harder insofar as she wasn't pushed at all," Mr Byrne (81) said last night. "I don't know whether that was by agreement.
"There were a whole host of questions which were not even put to her. I thought it was a typical 'getting to know you' interview.
"I thought she looked very well and spoke very well. It was a bit of a PR campaign, and what did you expect?
"But it was a bit of a coup to have her on so quickly. I suppose that has some value and there was a curiosity in her."
But RTE staunchly defended the interview. A spokesman for the Irish state broadcaster said McCollum made "frank admissions about the damage her actions may have caused".