Police sources stated that they have pinned down their investigations on a group of seven youths, who usually loiter in the shacks of Anjuna beach, where the girl's body was found on February 18.
"Detention of three is made while we are on look out for four others," a police official stated.
Scarlette Eden Keeling was found dead and her semi nude body was found on Anjuna beach.
Her family members pointing out to the bruises on her body had contended that it was a case of rape and murder, not an accidental death due to drowning as being established by police initially.
After intervention of Goa Chief Minister Digamber Kamat, the police had conducted second autopsy on her body which clearly mentioned the possibility of a murder.
Police sources confirmed that a gang of seven boys are suspected behind the incident as they were seen with her few hours before her death.
The investigations have revealed that Scarlette was partying with these boys at a local shack till 0400 hrs on the fateful day.
Police sub-inspector Nerlon Albuquerque, who was initially investigating the case that was later handed over to police Inspector Braz Menezes, is in the line of fire after the state Tourism Minister Fransisco Pacheco sought his dismissal.