NEW DELHI, INDIA - INDIAN police have charged a man with the murder of British teenager Scarlett Keeling in the resort state of Goa, the Press Trust of India reported early on Thursday.

Placido Carvalho was arrested and charged with the killing of the 15-year-old more than three weeks after her bruised and partially naked body was found on a beach, PTI said, quoting police sources.

Police in the former Portuguese colony had initially insisted the girl had drowned in the choppy waters of the Arabian Sea but a second autopsy demanded by Ms Keeling's mother concluded she was murdered.

The PTI report said Carvalho, a 'prime suspect,' had been denied bail. He reportedly told police he saw Ms Keeling drunk in the hours before her murder but with another local man.

Police have already charged another man, 29-year-old Samson D'Souza, with statutory rape.

D'Souza, who denied rape but reportedly admitted consensual sexual contact, told a court that Ms Keeling was still alive when he left her.

The PTI report said D'Souza and Carvalho were among a group who were seen with Scarlett the night before her corpse was found.

Hours before the arrest, local police insisted the case was close to being cracked.

'We are moving with a very fast speed in the positive direction of solving this case,' Goa police official Kishan Kumar said on Wednesday.

The coastal state's chief minister, Digambar Kamat, had also said he expected the case to be wrapped up in 'one or two days.' But he has also vowed to probe local police, and one officer involved in the early stages of the investigation has been stripped of his authority.

Ms Keeling's mother, Fiona MacKeown, came to Goa from Devon in southwest England in November with seven of her nine children for a six-month stay.

She accused police of trying to stall a proper investigation from taking place.

'It's been a farce from the beginning,' the 43-year-old said on Tuesday.

But the victim's alleged lifestyle of drinks, drugs and sex have been played up by the Indian press, and officials have also questioned why Ms MacKeown left her daughter in Goa while she travelled in a neighbouring state.

'The mother should have taken care of the child since she was a minor,' Mr Kamat has said. 'She left a minor girl in someone else's custody. Tourists should be more responsible and careful.'

The month before Ms Keeling's body was found on February 18, the federal government asked authorities in popular tourist destinations such as Goa to review security measures after a spate of highly publicised sexual attacks on foreigners.

Goa receives about 400,000 foreign tourists each year - ranging from hedonistic backpackers to well-heeled visitors. -- AFP