We are appealing for witnesses and dashcam footage after officers were called to an incident on the M11 on the evening of Monday 11 April.
Officers attended reports of an unattended dark-coloured van on the hard shoulder of the M11 between the Redbridge roundabout and Loughton shortly after 8pm.
Once at the scene, officers found a man within the vehicle who required hospital treatment. He was taken to a nearby hospital.
He has now sadly died, and we are treating his death as unexplained.
We are now appealing for anyone who noticed any suspicious behaviour on the M11 between the Redbridge roundabout and Loughton between 7.30pm and 8.10pm on Monday (11 April) or caught any suspicious behaviour on dashcam to come forward.
If you have any information you can submit a report online or use the 'Live Chat' button to speak to an online operator between 7am-11pm.
You can also call 101. Please quote incident 1121 of April 11.