Sandip Moneea, 52, appeared in court on the Indian Ocean island on Wednesday on a charge of conspiracy to commit larceny in relation to the McAreaveys’ hotel room.
Last month, another former hotel worker – ex-security guard Dassen Narayanen – was charged with the same offence.
Moneea, of School Lane, Petit Raffray, and Narayanen are charged with conspiring with each other to steal a magnetic key card to the room occupied by Mrs McAreavey and her husband to commit larceny.
Mrs McAreavey, 27, was strangled in her room at the Legends Hotel in Mauritius on January 10 2011.
The teacher, who had married husband John 10 days earlier, was attacked after she returned to her room alone and disturbed a burglary.
No-one has been convicted of murdering the daughter of Gaelic football manager Mickey Harte.
Moneea’s barrister Neelkanth Dulloo told the PA news agency that he believed the police were wrong in their approach.
“It’s a hopeless case for them and we will make sure that the rule of law is followed,” he said.
“Police is under pressure from higher quarters. They are making the same mistakes they did 11 years ago.”
Narayanen, 37, from Royal Road, Plaine des Papayes, was remanded in custody in March.
Moneea and another man were found not guilty of Mrs McAreavey’s murder after a high-profile trial on the holiday island in summer 2012.
He has always denied wrongdoing
Moneea and his co-accused in the murder trial, Avinash Treebhoowoon, worked as cleaners in the hotel at the time of the killing.
Narayanen, who has denied wrongdoing, has been admitted to hospital several times for mental health issues during his detention and his lawyer has criticised the way he has been treated by police.
Barrister Vikash Teeluckdharry wrote to the prime minister of Mauritius, Pravind Jugnauth, on Tuesday, outlining 10 specific concerns about his client’s detention.
The letter, seen by the PA news agency, said: “I fervently call for your intervention in order to better protect the integrity of the criminal procedure in Mauritius, particularly the police procedures in the absence of the modern safeguards, which are available in more advanced countries such as Britain.”
Mr Teeluckdharry outlined further concerns about the handling of the overall investigation. He said he would be sending a copy of the letter to Northern Ireland’s Justice Minister, Naomi Long.
Police in Mauritius have previously denied mistreating Narayanen in custody.