Harald Hoyer, a German chef, maintains that he is the man seen in CCTV footage viewed by the jury in Michaela McAreavey's murder trial and that if necessary he would travel to give evidence at the trial.
According to RTE, while the prosecuting counsel and a senior police officer said on Friday that the couple featured in the footage from the hotel were two German tourists, the defense is claiming that the couple are John and Michaela McAreavey.
If what the defense says is true, then John McAreavey has provided contradicting details of his movements to the court, which would undermine the entire prosecution case.
Speaking from Munich, Mr Hoyer said that he would be prepared to give evidence in court in Mauritius.
"Yes, I would certainly do that. I could also give an affidavit here in Germany, I could do it in the German legal system or with the German police. But of course I would do that," he said.
"If I could definitely help the husband of Michaela I would do that, yes."