IRISH backpacker Danielle McLaughlin was gang raped before being slashed to death with a broken beer bottle, according to her family's lawyer.
The explosive claims cast huge doubt on the police investigation in Goa, India, where the British-Irish dual citizenship holder was murdered last week.
And it could mean that while prime suspect Vikat Bhagat, 23, remains in police custody, other alleged attackers could be long-gone, reports The Sun.
"Danielle was 5'8" tall and she was really strong. This fellow Bhagat, he does not look strong and muscular", lawyer Vikram Varma said.
"I doubt he had the strength to overcome Danielle on his own. If she was intoxicated there would have been no need for the terrible injuries she suffered", he added.
"There has to be more than one person involved. I have no doubt."
It comes as Mr Bhagat appeared in court on Monday charged with a separate spate of thefts on tourists. He will face rape and murder charges later.
Meanwhile, a man who was seen with Ms McLaughlin in haunting final pictures has denied having any role in her killing.
The last known pictures of the much-loved jetsetter show her in a bikini top and holding the hand of Rajesh Sarokomart Pant - a local taxi driver known as 'Kanar'.
The 37-year-old reportedly spent hours drinking with Ms McLaughlin, who lived and worked in Liverpool before going travelling, but denies he was holding her hand.
He is one of six men brought in for questioning by police investigating her murder and has since been released on bail.
He said he had been drinking with the traveller in Green Park bar on the night of her death.
Mr Pant claims shortly after that he went home and Ms McLaughlin got on the back of a scooter belonging to suspect Bhagat, who remains in custody.
His wife Rishma, 31, said he had not been with Ms McLaughlin that night.
Other partygoers told how a group of locals were "glued" to Ms McLaughlin, who had painted her face, at the bash for local expats.
The intervention of Mr Varma, who also worked on the case of 15-year-old Scarlett Keeling's 2008 murder, is not the first time police investigating Ms McLaughlin's murder faced criticism.
The latest claims come as Ms McLaughlin's friends revealed she was surrounded by a group of "leering" Indian men at a party hours before she met her tragic end.
On Friday it emerged up to 30 people trampled through the crime scene.
Police have denied mishandling the case.
Deputy Superintendent Sammy Tavares said: "There is no question of polluting the crime scene. We always sanitise the area of crime. We call the crime scene experts and forensics.
"But in this case it might have taken a couple of hours for the team to turn up.
"The accused was identified by some witnesses, but it was done with due diligence."
Police revealed Ms McLaughlin was strangled and slashed to death after she was raped.
Her body was discovered naked in a field near a beach after her face was mutilated with a broken beer bottle.
A post-mortem revealed evidence of sexual assault and "compression of the neck", local media said.
Umesh Gaonkar, of Goa Police, said the examination showed that Ms McLaughlin suffered cerebral damage as well as constriction of the neck, causing her death.
Her heartbroken friends have now set up a GoFundMe page to help cover the costs of repatriating her body.
The page has already raised more than £33,000 ($53,000) for her family.
Mr Bhagat, who appeared in court on 19 separate theft charges, admitted to police that he killed Ms McLaughlin but denied raping her, according to police.
This article first appeared in The Sun.