The Independent Police Complaints Commission has revealed that a gun was found in Mohammed Yassar Yaqub's car on Monday night.
The IPCC investigation into the fatal police shooting in Huddersfield continued today.
Father-of-two Yaqub, 28, of Crosland Moor , was shot by a West Yorkshire Police firearms officer during a planned police operation at Junction 24 of the M62 motorway shortly after 6pm on Monday. He died at the scene.
A statement from the IPCC said that what appears to be a non-police issue firearm was discovered in the vehicle in which Mr Yaqub was travelling, and is being further examined.
It said: "Mr Yaqub’s family has been informed and will be kept updated by an IPCC family liaison manager. A post mortem is due to take place tomorrow (4 January). HM Coroner has been informed.
"IPCC investigators are continuing to seek any relevant CCTV footage. Initial accounts from police officers involved have been obtained."
IPCC Commissioner Derrick Campbell said: “My thoughts are with Mr Yaqub’s family and all those affected at this difficult time. Though in its early stages, this investigation is making good progress but will be complex.
"We will be working hard to establish exactly what happened and would ask for patience while our investigation continues.”