The family of John McAreavey has appealed for privacy and cautioned members of the media about reporting the trial of two hotel workers accused of the murder of his wife, Michaela.
The 27-year-old Co Tyrone woman was killed while on her honeymoon last year.
The only daughter of Tyrone Gaelic football manager Mickey Harte was found strangled in her luxury hotel room.
She had momentarily left her husband at the poolside to return to their room at the five-star Legends Hotel.
Her body was discovered a short time later in the bath.
At 6.30am Irish time today, two defendants were brought in prison vehicles to courtroom number 15 at the Supreme Court in Mauritius.
There were chaotic scenes outside the courtroom as the two accused arrived.
Security has been ramped up around the old French colonial court building for what is one of the most high-profile criminal cases ever held on the island.
Avinash Treebhoowoon, 30, was a room attendant at the hotel, while Sandip Moneea, 42, was a floor supervisor.
John McAreavey and relatives of the accused were also jostled as police struggled to control the flow of people into the courtroom.
Mr McAreavey will be one of the 30 prosecution witnesses in the trial.
He travelled to Mauritius with his father, Brendan, his sister Claire and his brother-in-law, Mark Harte.
Nine jurors have been selected. The six men and three women will vote to select a foreman.
Mr McAreavey sat in court for a short period but was then asked to leave because he is a witness in the case.
Though most Mauritians speak a variant of French as their first language, court proceedings are being heard in English.