Haren Pandya was a BJP politician and Gujarat Home Minister, murdered in unclear circumstances in 2003 in Ahmedabad. To date Pandya's murderers remain unknown: 12 people were convicted for the murder by a special anti-terrorist court, but had their convictions overturned. It is widely held, including by Haren Pandya's widow, that they were framed. Several sources have alleged that Tulsiram Prajapati, himself killed in a fake encounter in 2006, was involved in Pandya's murder, but if so, the reasons remain unclear.
Factional infighting within the Gujarat BJP meant that Pandya had fallen out with Narendra Modi, and once Modi had risen to prominence, Pandya was sidelined. Pandya apparently believed the Gujarat pogroms of 2002 were orchestrated by Modi, and Pandya's father repeatedly alleged, before his death, that Narendra Modi was responsible for his son's murder. It has also been claimed by a former senior police officer that Modi's right-hand man Amit Shah played a role in the murder.
References:
•Why do we STILL not know about the killer of Narendra Modi's Minister, Haren Pandya? by Sanjeev Sabhlok.