Gagneja, 65, breathed his last at 9.16 AM at the Hero DMC Heart Institute, Dr G S Wander, Director of the Institute, said.
Brigadier (retd) Gagneja was attacked by bike-borne assailants on August 6 in Jalandhar. He was rushed to the Ludhiana hospital in a critical condition the next day.
After police failed to get clues in the murder of the Vice President of the Punjab unit of the Sangh, the case was handed over to the CBI recently.