Investigations are continuing and police are also working with the Highways Agency to clear the carriageways of debris so that repairs and resurfacing can be carried out.
No definite time for the reopening of the motorway can be set yet but it is likely to remain closed throughout the morning rush-hour.
Part of the M25 has been closed following a fatal crash. One person was killed and three others were taken to hospital following the accident at 1.50am today in Essex.
The motorway is still closed between junctions 25 and 27, and is likely to remain shut for most of the morning.
Plans to unveil a two billion pound boost to improve roads across London and the South East will be unveiled by the government later today.
The money will go towards expanding junctions on the M25 as well as building a new bypass on the A27.
Work began at 6am today to remove 27 toll booths on the southern end of the Dartford Crossing.
The booths on Britain's busiest motorway are being scrapped and replaced with an electronic payment system.
The changes at the Dartford Crossing on the M25 east of London are designed to improve traffic flow.
But the removal of the 27 toll booths at the southern end of the crossing will result in roadworks until March 2015.
And car drivers using the crossing will from today face a higher daily charge - with the fee, also payable by phone or post as well as online, going up from £2 to £2.50. Charges are also rising for goods vehicles.
The Highways Agency is hoping for a minimum of congestion at the start of the new system.
An agency spokesman said: "We're starting at 6am on a Sunday when traffic will be comparatively light and there will be plenty of signs up to tell people about the new arrangement.
"Monday morning will be more of a test but we are trying to do everything we can to let people know about the changes."
Parts of the M25 that were closed on Friday, following the partial collapse of its carrigeway has reopened.
The incident which took place near Leatherhead between junction 9 and 10 anticlockwise caused long delays until late that evening.
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Motorists have taken to social media to bemoan their miserable Friday commutes, as three lanes of the M25 remain closed following rain damage to the road surface near Leatherhead this morning.
Literally spent the whole of my day in a car trying to get back to Brighton from Wolves, took me 1hour30 to move 2 miles on the M25...
Arrggg, terrible day, missed my train to Paris as stuck on M25 for 2 hours, Eurostar customer service made things 100 times worse, cheers!
Delays on the M25 are set to continue until this evening as three lanes remain closed anti-clockwise between Junctions 9 and 10 near Leatherhead.
Motorists are being advised to avoid the area if possible, due to the long delays. Passengers travelling to Gatwick Airport are being urged to allow extra time for their journey or take alternative routes.
The Highways Agency is still trying to repair an earlier road collapse and determine the cause of the defect.
"Long delays are likely until the motorway fully reopens"
The Highways Agency is running out of time in its efforts to complete a carriageway repair ahead of the Friday night rush. Three lanes have been closed all day on the anti-clockwise section near junction 9 at Leatherhead, after the road surface was damaged in heavy rain.
Queues are already tailing back to junction 12, and two more layers still need to be added to the road surface before it can be reopened, with time needed for each layer to dry before the next one can be started. Anyone who can avoid the area is being advised to find an alternative route.
The M25 in Surrey is likely to remain partly closed through the rush hour, as the Highways Agency struggles to finish a repair to the anti-clockwise carriageway near Leatherhead. Watch the video to see an aerial view of the area being fixed, plus a flyover of some of the traffic already tailing back. Local police are advising people to avoid the motorway if at all possible.
Severe delays as the M25 is reduced to one lane between Junction 9 and 10 anticlockwise. Emergency repairs are taking place after an earlier road collapse. Restrictions on the route will last until 4pm at least.