Our live feed has now finished.
- The "incident", clockwise between junctions 23 and 24, is currently being dealt with by police.
- The nature of the "incident" is not yet clear.
- There were delays of around 40 minutes against expected traffic, according to National Highways.
- Police have been contacted for more information.
- Two lanes were closed initially, before one quickly reopened and the other reopened by 1.45pm.
- A lane was also closed clockwise between junctions 18 and 20 due to a separate crash, near Chorleywood.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article