The Derry-based solicitor with the 'Truth for Danielle' campaign has made an international appeal for video and photographic footage from those who attended the Holi festival in India in March.
Danielle McLaughlin, 28, was found raped and murdered in a field near Canacona in Southern Goa on March 13th.
To date, one person has been charged in relation to the Buncrana native's death.
Speaking on RTÉ's 'Morning Ireland,' solicitor Desmond Doherty, said that he had spoken with the chief investigating officer in the investigation, before the Easter break.
He said: “He assured me at this point, I have to make this very clear, that subject to any further evidence that comes to light, that they have one individual who they are focusing on and who they have charged and they are not looking for anyone else at this stage.”
The solicitor added that there “is a lot of innuendo and rumour and suspicion about other individuals being involved.”
He appealed for all those who were present at the festival to forward their video and photographic footage to them.
He said that one of the things that they have noticed from the footage that they have viewed, to date, is that people on cellular devices continued to film and photograph all events.
“There's a wealth of evidence out there,” he said.
He added that he had to have confidence inthe justice system in India.
“I am an officer of the court in this jurisdication. It is not for me to criticise the legal system in another country,” he said alluding to issues relating to the legal systems in both the north and south of Ireland.
He added that it was hoped that with the footage that they would receive from those who filmed events in India, that they may be able to assist the investigation in India.
“We have to contribute to the legal process. We have to do our best.
“If we get any information, we will share it with the appropriate authorities,” he said.
Anyone with any information or footage may firstname.lastname@example.org or you can email email@example.com.