Two more employees of Thane Municipal Corporation (TMC) were arrested in connection with the building collapse which claimed 74 lives, police said.
With these arrests, the number of those taken into custody rose to 17, they said.
TMC's suspended clerk Subhash Waghmare and Ramdas Burud (the driver of arrested deputy municipal commissioner Deepak Chavan) were arrested by the Crime Branch on Sunday.
According to police, the duo had direct contacts with the builders who allegedly distributed cash to officials to "safeguard" the illegal seven-storey building at Lucky Compound in Shilphata area in Thane and other structures from being razed by civic authorities.
Waghmare had been suspended on January 30 after he was held by the Anti-Corruption Bureau, Thane unit, for allegedly taking a bribe of Rs 30,000 from a housing society in Diva.
His name was also found in the diary of builder Jameel Shaikh who allegedly bribed civic officials to overlook violations in the construction of the illegal building that crashed on April 4.
Police said Burud allegedly demand money from Shaikh, who maintained a record of the cash paid to officials.
Builders Abdul Salim Aziz Siddiqui and Jameel Ahmad Jajaluddin Shaikh, who constructed the structure, are among those arrested. They face the charge of culpable homicide not amounting to murder and criminal conspiracy among others.
Three officials of TMC, one of them a deputy municipal commissioner, an architect, corporator Hira Patil, a building material supplier and a local journalist, are among those arrested earlier.