The directors, Jitendra Jain and Ketan Shah, have already been arrested in several cases of cheating and forgery.
EOW (housing unit) arrested Naresh Rajpurohit (52) under IPC sections for cheating, criminal breach of trust and conspiracy, and under Maharashtra Flat Ownership Act (MOFA). He was remanded to police custody.
Sources said his arrest will help unearth how he allegedly helped Jain start construction firms, accept bookings from investors/flat-buyers, transfer the money to several bank accounts and siphon around Rs 600 crore.
Police said Rajpurohit handled the company's finances and audits since 1993. "We alerted Enforcement Directorate (ED) to help us unearth proceeds of the crime. We hope his arrest will help us join the dots,'' said EOW investigating officer, P Padir.
The fresh complaint was filed by three flat-buyers from Khar involving Rs 6 crore.