Under Peruvian law, McCollum Connolly and her fellow smuggler Melissa Reid are free to walk free from the Ancon 2 prison, having served a third of their sentence.
Now the Irish Mirror reports she has been struck by a tropical illness.
"Michaela has been brought to hospital in the prison. She has a tropical illness but we don’t know what it is," said an inmate.
“We really hope she is OK. This [illness] is pretty regular in here, especially with the foreigners.”
McCollum Connolly is said to be able to speak Spanish now and is reportedly popular among the other inmates.
Reid and McCollum were working in Ibiza when they claim they were forced to board a flight with 24lb of cocaine in food packets hidden inside their luggage.
They were caught on August 6 2013 and later pleaded guilty to drug smuggling, each receiving a jail term of six years and eight months.
The repatriation of McCollum to Northern Ireland was approved by Stormont's justice minister in January this year but, like Reid, she remains in jail in Lima for now.
The pair had previously been held at Virgen de Fatima prison but were later moved to the Ancon 2 jail, where conditions are said to be cramped, with poor sanitation and toilet facilities.
Reid's father Billy said recently that the impact of his daughter's crime on his family had been "horrendous".
He said: ''It's horrendous to see your daughter in handcuffs and the living conditions that she has to put up with. Melissa has spent her own 20th and 21st birthdays in prison in Peru.
''She missed the significant event of her only brother's wedding. Events such as Christmas are non-existent for us. There'll be no celebrations in our house, there'll be no Christmas tree until we get her back home.''
Mr Reid spoke out in a video warning of the consequences of drug offences abroad.
More than 700 British nationals were arrested for drug-related crimes in 2013-2014, according to the Foreign Office.