Part of the M25 in Hertfordshire was closed on Sunday after a woman died in a horrific early morning crash - moments after a police chase.

Multiple vehicles are thought to have been involved in the smash at 4am between junction 22 (London Colney) and 21A (North Orbital Road/St Albans).

The Independent Office for Police Conduct will investigate the lead up to the crash which involved a van and three cars. Police officers stopped pursuing the van before the fatal crash.

Motorists were advised to avoid the stretch as the M25 was closed from junction 22 to junction 25 from 4am to about 10pm on Sunday.

Herts Advertiser: Two police pursuits preceded the crash.Two police pursuits preceded the crash. (Image: UKNIP)

In a statement released to the Sun yesterday, Hertfordshire Police said: "The M25 remains closed between junctions 22 (London Colney) and 21A (North Orbital Road/St Albans) following a collision at around 4am this morning. 

"Officers were in pursuit of a van before the van was involved in a collision with three other vehicles.

"No police vehicles were involved in the collision and the pursuit had been stood down prior to the collision.

Herts Advertiser: A man and a woman have been confirmed dead following the crash.A man and a woman have been confirmed dead following the crash. (Image: UKNIP)

"A woman has sadly passed away and her family are being supported by specially trained officers.

"As a matter of course, the incident has been referred to the Independent Office for Police Conduct.