The trio were produced before a local court which remanded them in police custody till January 22, he added.
Police have arrested three persons for allegedly sexually assaulting and murdering a 7-year-old, almost a month after the minor's decomposed body was found along Eastern Freeway near suburban Wadala.
The Crime Branch sleuths arrested Krishnanarayan Yadav (22), Tausif Ali Taufik alias Shaikh (24) and Mehmud Ali Sadaf alias Sayyad (22) on Saturday night, an official said on Sunday.
The trio were produced before a local court which remanded them in police custody till January 22, he added.
Highly-decomposed body of the boy was spotted lying in a pit on December 24, 2015 by some labourers who were laying cables at the spot.
According to police, the trio allegedly kidnapped the minor sometime in October last year from a Wadala slum after luring him with sweets.
All the accused, in an inebriated condition, had unnatural sex with the boy before strangulating him, police said, adding that they dumped his body in the pit along the Freeway.
A case of missing person had been registered by Wadala TT Police in this regard.
Later, the boy was identified by his parents on the basis of his clothes.
The accused persons are residents of Wadala and Antop Hill areas in the city.