Traffic was brought to a standstill this afternoon on the M1 in London amid concerns over a man's welfare.

The motorway was shut down between junction 1 (Brent Cross) and 5 (Watford), leading to serious congestion.

A Hertfordshire Constabulary spokesperson urged motorists to steer clear of the area.

They said: "Police are dealing with a concern for welfare of a man on the M1.

"We would ask motorists to please avoid the area at this time while police deal with the incident."

The London Ambulance Service and the East of England Ambulance Service were called.

Brent & Kilburn Times: A Highways England image of the M1 between Junction 1 and 2 northbound. (Image: Highways England)A Highways England image of the M1 between Junction 1 and 2 northbound. (Image: Highways England) (Image: Highways England)

Disruption lasted for hours.

Paul Ridley, who was on a coach bound for Shropshire, reported being stationary north of Junction 4 for more than two hours.

He said: "We’re about 100 yards from the police stoppage. We were pulled to a halt at 3.10pm.

"In situations like this you can only feel for those involved and we wait patiently.

"Everyone is in good spirits after a short break to London to see Abba Voyage and Christmas Shopping!"

For several hours, traffic was diverted north via the A406, A41 and A1.

Highways England had originally said the gridlock was expected to clear between 5pm and 5.15pm

In fact, National Highways began to release traffic shortly before 4.45pm.