The mother of a British girl found dead in Goa has urged a Briton who fled the Indian state to get in touch.

Fiona MacKeown believes that the man witnessed the rape of her daughter, Scarlett Keeling, 15.

She told The Times that he had confided in another foreign resident of Goa, who then contacted her, but that the man had since left in fear of his own life. “We urge him to come forward because this information could be vital to this case,” she said.

Her appeal came as the authorities in Goa agreed to allow a second post-mortem examination of Scarlett's body and to decide whether to open a criminal case within the next three days. Police also revealed that they had questioned an employee of a beach-front bar who they said was seen leaving the bar with Scarlett at about 4am on February 18, the last time she was seen alive.

They said they could not detain any suspects until they had officially opened a criminal case — and they could not do that without another post-mortem examination.

The first autopsy concluded that Scarlett drowned, and police had been ready to close the case last week until Mrs MacKeown protested to state officials and the media. She said that the autopsy overlooked multiple scratches and bruises on her daughter's body, and accused the investigating officer of trying to cover up a rape and murder.

The case has thrown a fresh spotlight on the issue of foreign women's safety in India after a series of sexual assaults on tourists, including several Britons, in the past three months. It also highlights the darker side of Goa, where palm-fringed beaches, a laid-back atmosphere and plentiful drugs have made it a favourite destination for young backpackers.

Martin Fraser, another British citizen, died in Goa last month, officially by drowning. His family's lawyer said there were injuries on his corpse suggesting he had been assaulted.

Scarlett had been staying with Julio, a 25-year-old local tour guide with whom she had a sexual relationship, while the rest of her family travelled in the state of Karnataka. The guide said he last saw Scarlett at 8.30pm on February 18 when he drove her to a restaurant to meet a Spanish friend called Ruby. Witnesses say that Scarlett and Ruby went out and returned drunk to the restaurant at 1am. Scarlett then left alone, they say.

Police said that Scarlett was seen arriving at Lui's, one of about two dozen beach “shacks” that line Anjuna beach, at about 4am, and leaving with one of the barmen soon afterwards. Locals found her half-naked body at about 6.30am close to the bar. Her shorts and underpants had been removed and her bra-top pushed up around her neck.

Police sources declined to say if either Lui, the owner, or Samson Da Souza, another employee, was the man seen leaving with Scarlett.

Regulars described Lui's as a low-key bar where predominantly Western tourists came to drink or play pool, rather than to dance or pick people up. But they said drugs were available on or around the beach and were often sold by “shack boys”.

Mrs MacKeown, who has eight children, said she had not realised that Goa had a seedier side. “We thought Scarlett was safe on the beach because she was surrounded by friends and with an older person to look after her,” she said.

Spiritual school

— Before being taken to Goa, Scarlett Keeling had been one of 22 pupils at the Small School in Hartland, near Bideford, North Devon, one of the country’s smallest secondary schools

— The school is a registered charity and describes itself as seeking to achieve “a balance between the academic, the practical, the artistic and the spiritual”

— Parents pay one third towards their children’s education costs and must agree to help with fundraising, management meetings and ‘clean-up weekends’

— Pupils at the school said Scarlett’s boyfriend, who lives in North Devon, was distraught at her death and claims that she had begun a relationship with her Indian tour guide

— A friend said: “Scarlett was a really popular girl. She was completely at home in the water – she grew up on the local beaches. It was hard to believe that she drowned accidentally”

Explore Asia News

• China News

Times Recommends

• Appalachian voters lean towards Obama
• Iraq: Battle for business begins
• 50 dead in seven days in Mexico's drugs war