Skin tissue found under the fingernails of strangled honeymooner Michaela McAreavey could prove crucial to the police case against the three men charged in connection with her murder.
It is understood DNA tests on forensic evidence recovered from the body of the 27-year-old teacher are due to be completed by the end of the week.
The newlywed, who was the daughter of Mickey Harte, manager of Ireland's Tyrone gaelic football team, fought for her life against her attacker in her room in the luxury Legends Hotel in Mauritius, the island's police said.
Police chief Dhun Rampersad said: "From what we have obtained from her nails, the collections we have obtained from her nails, it looks like there may have been some struggle."
On Monday her husband of only 10 days, John McAreavey, found his bride's body in the bath with the water running. It is understood the Irish language teacher from near Ballygawley, Co Tyrone, interrupted burglars who had gained access to the room using an electronic key card.
Mr Rampersad said investigating officers would prefer Mr McAreavey, who was initially arrested but quickly ruled out as a suspect, to stay on the island for a few more days, until early next week, to help with the inquiry. This may hamper the families' hopes of returning Michaela's body home by the weekend.
Three workers at the hotel have been remanded in custody in connection with the killing. Two face murder charges and one conspiracy to murder.
The Mauritius Police Force said the two men charged with the murder are Avinash Treebhoowoon, 29, a room attendant from Plaine des Roches, and Sandip Moneea, 41, a floor supervisor from Petit Raffray. Room attendant Raj Theekoy, 33, from Ramnarain Cottage, faces the conspiracy charge.
The brief court hearing in Mapou on the north of the island heard claims that one of the defendants had been beaten by police officers during questioning, an allegation magistrate Bono Mally pledged to look into.
They were remanded in police custody for a week to return to court next Wednesday, when they are expected either to be formally charged or released. Mr Rampersad said the evidence against the three suspects was circumstantial.