The body of a man was found on land near the motorway on Friday morning, and since then, road closures have been in place.
One lane has been closed on the slip road at junction 4b, with another lane closed on the M4 from junction 4b westbound. The slip road exit on the M25 to the M4 is also closed.
In addition to this, on Sunday morning, the M25 clockwise and anti-clockwise slip roads onto the M4 Westbound will be fully closed.
The M4 Junction 4b/ 5 on the westbound carriageway will be down to one live lane.
As such, drivers are advised to take alternative routes if possible and to avoid the area if they can.
Police would like to thank everyone for their continued patience while we carry out this important investigation.