"Prime suspect Placido Carvalho, who was arrested last night, has confessed that he gave her drugs, raped her and left her on the beach. As the girl remained unconscious, she died during the high tide," a senior police officer and in-charge of the investigations, said Thursday morning.

The half-clad body of Scarlett was found on Goa's popular Anjuna beach on February 18.

Meanwhile, Sub Inspector Nerlon Albuqurque of Anjuna station, who was already stripped of his "authorities", was on Thursday suspended for alleged laxity in investigating the case.

The family of the 15-year-old girl, which had earlier expressed doubts over the police role, expressed happiness at the progress in the investigations.

The official said Carvalho, who has been booked on murder charge, and the other arreseted persons Samson D'souza, have both confessed to raping the 15-year-old few hours before she was found dead on the beach.

Thorough interrogation throughout last night confirmed that the girl had consumed high doses of cocaine and alcohol when she entered the beach shack during wee hours on the fateful day and was then given ecstasy tablets by Carvalho, police said.

Carvalho then allegedly raped the girl, who was in a semi-conscious state and left her on the beach, he said.

Prior to that, Samson D'souza, 29, a barman working on the shack, was seen in a "compromising position" with the girl by an eye witness.

After Scarlett was found dead on the Anjuna beach, her family had contended that she was raped and murdered.

Initially reluctant to treat it as a murder case, Goa police carried out a detailed probe after a second autopsy was conducted by a team of doctors here following a demand by the girl's mother Fiona Mackeown.

Expressing happiness over the progress of the investigations in the case, the British family's lawyer said the state should continue probing into the `criminal-police-politician nexus' flourishing in the tourist hotspot.

"We are happy that police have conducted investigations properly but we want that police's act of misguiding Fiona Mackowen (Scarlett's mother) should also be probed," Vikram Varma, lawyer for Scarlette's family, said this morning.

He said the arrests have been made in the right direction.

"But the key for the entire incident is the nexus between criminals, police and politicians which should be unearthed," he said.

The family members feel that police have done half their job. "Scarlette's death investigation was just a part of the entire case. The other half is police complicity in trying to hide the crime. The entire episode of abetment of crime by the police needs to be investigated," he said.

The lawyer said the reason why Scarlette's mother was upset was because police were lying to her.

On March 11, before Alburqurue was stripped of all his "authorities" investigations into the case were shifted from him to a senior police inspector Braz Menezes.