Mumbai Police on Friday arrested accused Mauris Noronha's private bodyguard, whose pistol was allegedly used in the murder of Shiv Sena (UBT) leader Abhishek Ghosalkar.
Amrendra Mishra, Noronha's bodyguard, has been arrested under the Arms Act and will be presented in the court on Saturday.
Mauris Noronha, popularly known as Mauris Bhai, allegedly shot dead Abhishek Ghosalkar, the son of a Shiv Sena UBT leader, while doing a Facebook live with him. The attack took place at Mr Noronha's office.
The attacker then turned the gun on himself.
Morris, who used to keep his bodyguard's pistol with him, had used the same weapon for the crime, said police.
Mr Ghosalkar was invited to Noronha's office for an event which was being webcast. The motive of the shooting is not clear yet.
The murder comes days after a BJP MLA was caught on camera firing at a leader of the Eknath Shinde faction.