An Essex Police spokesperson said: “The road is likely to be closed while emergency services respond to the collision and investigate what has happened.
“There was a less serious collision on the other carriageway at around a similar time, but we believe that was a separate incident.
“Please avoid the area if you can, and if you saw what happened or have any dashcam footage, we need you to contact us.
“If you have any information, CCTV, dash cam or other footage in relation to this incident, then please get in contact with us.
“Please quote incident 1161 of 1 January.
“You can let us know by calling 101 or submitting a report on our website or by using our online Live Chat service, which is available 24 hours a day, seven days a week.
“Visit www.essex.police.uk/digital101 to find out more about our online reporting services.
“If you would like to make an anonymous report you can contact independent charity Crimestoppers, by visiting their website or by calling 0800 555 111.”
