A special investigation team (SIT) has been formed by the Mumbai police's crime branch to probe the murder of a builder, who was shot dead in broad daylight last week in neighbouring Navi Mumbai, police said today.

"A SIT team, comprising officers from four crime branch units, has been formed. The team is actively working on builder Sunil Kumar Loharia's murder case," a crime branch official said.

Loharia (50) was gunned down by two assailants outside his office at Vashi in Navi Mumbai on February 16.

Locals had caught one of the assailants, Vishwakarma Shettiar (35), from the spot while the other, Wazid Qureshi (28), was later arrested from his home at Mumbra town in Thane district.

On Sunday, a retired police inspector and former 'encounter specialist' - Emmanuel Amolik (62) - was arrested for allegedly ordering the killing of the builder, police said.

The motive behind the killing was suspected to be business rivalry, they said.

However, even as the three persons were arrested by Navi Mumbai police, Loharia's family demanded the state government that the case should be transferred as they did not trust the police personnel there.

Following the demand, the case was handed over to city's crime branch.

On Monday, Loharia's son Sandeep had alleged to have received a call on his cellphone where the unidentified caller threatened to "kill my family if I do not stop from going to the media."

The caller also stated that his father was "silenced" for trying to expose the "nexus" between the police, builders and officials of Navi Mumbai Municipal Corporation and its urban planning agency CIDCO, Sandeep had said.