By Karishma Vaswani
BBC News, Goa
Michael Mannion says he saw a man on top of Scarlett on the beach
Thirty-five year-old Michael Mannion from London has come forward as an eyewitness in the investigation into British teenager Scarlett Keeling's death in Goa.
I met him in Goa, and interviewed him for the first time on camera to reveal what he claims he saw on the night that Scarlett died.
The meeting was arranged by the lawyer representing Fiona MacKeown, Scarlett's mother. Vikram Verma telephoned my colleague, the BBC's South Asia Correspondent Damian Grammaticas in Delhi, to inform him that Mr Mannion was ready to talk to us.
I was asked to come to Mr Verma's home in Povorim in Goa. When my cameraman and I arrived, Mr Mannion was already there, sitting quietly in the corner of the living room, looking out of the window.
He seemed tense, and very nervous. He told me that he had been coming to India for 13 years, and that he had visited Goa since 2002, but that he had never felt so scared before in his life.
Michael told me he was already at Luis' Bar on Anjuna Beach in Goa when Scarlett entered.
"Scarlett entered the bar at approximately 3am in the morning. She fell over in front of the shack, and was helped into the shack by Luis Coutinho, the owner of the shack. She came into the bar in a very intoxicated state; her walking was very uncoordinated.
"She then proceeded to go to the backside of the shack, towards the kitchen area, where three local men were sitting chatting. She was in their company for about an hour.
"Then she came to the front of the bar and spoke to me and another guy who was there, and from that I ascertained that she was English and she was 15 years of age.
"It was pretty difficult to understand her, because she was very - well, she seemed very intoxicated.
I asked Michael Mannion if he had seen anyone giving Scarlett drugs, or whether anyone had offered her drugs that night in the bar. He said he had not seen anyone give her drugs. But he did add that before Scarlett left the bar, she told him she had taken drugs, but she did not say where they had come from.
'Left with man'
Michael said that Scarlett left the bar with a man at around 5am that night.
But Michael says that when he left the bar a few minutes later, he saw the man who left with Scarlett driving off on his scooter - and in its headlight beam "I saw Samson D'Souza on top of Scarlett.
"After that I was in a complete state of total panic, shock, I just got on my bike and rode off. "
Two men have been arrested over Scarlett's death
I asked Michael what happened the next day after he had heard that Scarlett's body had been found.
"Initially I did nothing, then two of the people working in the shack were called in for questioning, And I was told by another local not to come, not to say anything. "
Michael's version of what happened to Scarlett that night is not very different from what the local police are saying happened to her
But when Scarlett's body was first found on Anjuna beach outside Luis' Bar, police here said she had drowned. It was only after Scarlett's mother Fiona MacKeown insisted her daughter had been raped and murdered that local authorities detained two men for their involvement in the case. They will be in police custody for 14 days for further questioning.
Michael Mannion has told the BBC that he had been too afraid to come forward with his statement before this because he had heard rumours that threats were being made against him because of what he saw.