Murdered Irish backpacker Danielle McLaughlin knew her suspected killer and the pair had exchanged messages on Facebook, Indian police have claimed.
The body of Ms McLaughlin (28) was discovered dumped in wasteland near the holiday hotspot of Canacona, Goa on Tuesday morning.
A post-mortem found that she had been raped, attacked with a broken bottle and strangled.
One man Vikat Bhagat (23) was arrested over the murder and police claim he has confessed to the attack.
Now the chief inspector running the investigation has told Independent.ie that "good staff, intelligence and CCTV" helped them crack the crime in less than 24 hours.
Inspector Filomeno Costa also claimed that Ms McLaughlin, from Buncrana, Co Donegal, had been in contact with her suspected killer.
"They knew each other before and they were friends. They were in contact with each other on Facebook.
"We don't have information as to when they first got in contact, we don't know how long they were friends."
Inspector Costa claimed that they are currently preparing a charge sheet in relation to Mr Bhagat and he said the suspect will be formally charged "in the next few days".
Sources have told Independent.ie that the suspect originally named a number of his friends as accomplices in the murder.
Inspector Costa said that he is the only suspect.
"There was only one person involved in this attack. We have looked at the medical evidence.
"We believe that he brought her to this location where her body was found and murdered her here."
Mr Bhagat has a long history of criminality with up to 16 previous charges or convictions for burglary and "banditry".
A post mortem was concluded on Thursday and Ms McLaughlin's remains have now been released to two friends who have travelled to Goa. She will now be transported by air back to Donegal.
Friends have created a fundraising page to pay for the repatriation of her remains. So far over €37,000 has been raised.
A Department of Foreign Affairs spokesman said last night that British embassy staff in India were providing consular services as Danielle was travelling on a British passport.
"As far as we can, we are supporting the family," the spokesman said.
Danielle's death has shocked the community in Buncrana.
Expats, backpackers and local people gathered at the murder scene for a solemn ceremony on Wednesday.
Danielle had travelled to Goa with a friend and they were in a village attending celebrations marking the Hindu spring festival of Holi on Monday night.
Her body was found on Tuesday, less than 2km from Palolem, one of the most popular beaches in southern Goa.
Buncrana parish priest Fr Francis Bradley said the circumstances made the grief of her family "particularly difficult".
"There is the heartbreak of the experience for Danielle's mother Andrea and her sisters, some of whom are very young," he said.
Danielle had a great love of travel - she had the "gene" for travel and was, in many respects "a free spirit", said Fr Bradley.
"She liked to experience other cultures," he added.
He said he had been seeking to support Danielle's mother as she tried to come to terms with "the enormity of her loss."
Her troubles were compounded by the huge geographical distance that separated her from those events, he added.
"Even amid the terrible loss and grief and sadness, there is still the light of hope that Danielle's life was not lived in vain," said Fr Bradley.
"Even in the tremendous outpouring of solidarity and support, care and concern from so many people near and far, it reminds us that goodness will still outshine everything else."