Senior Maharashtra Navnirman Sena (MNS) leader Atul Sarpotdar (51) passed away in Bandra's Lilavati hospital on Thursday evening after suffering a massive heart attack.
He is survived by his wife and one son.
Sarpotdar was a member of the MNS' Central Executive Committee.
Atul's father was Shiv Sena leader Madhukar Sarpotdar, who passed away at the age of 77 in Hinduja hospital in 2010 due to a cardiac arrest.
The Sarpotdars had been in the Shiv Sena for the last four decades before Atul broke rank to join Raj Thackeray.
Atul, who was a close friend of the MNS chief, was made the general secretary and in-charge of of party affairs in the Marathwada region in 2008.
Trade unionist Madhukar Sarpotdar, who was indicted by the Srikrishna Commission that probed into the 1992-93 communal riots in Mumbai, was a two-time MP and close aide of late Shiv Sena chief Bal Thackeray.