With today's arrests the number of those taken into custody for the tragedy rose to 15, police said.
The suspended assistant municipal commissioner, Shyam Thorbole, who was arrested today, had also been taken into custody earlier on January 23 by the Thane's ACB unit for allegedly accepting a bribe of Rs one lakh from a complainant at Diva, where the TMC had demolished around seven illegal chawls.
The Thane Police crime Branch today also arrested Hadisulla Rakbulla Choudhary alias 'Uncle', a partner of the developer of the sub-standard seven-storey building which crashed at Shil-Phata in Mumbra on April 4, killing 74 people and injuring 64 others.
On Tuesday, police had arrested Executive Engineer Subash Rawal and the Deputy Engineer Ramesh Inamdar in connection with the incident.
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.