The body of a man was recovered in the Thames just off Thamesmead yesterday afternoon.
Gravesend RNLI was called at 3.58pm to reports of a corpse in the water.
Lifeboat crews attended while a marine police unit recovered the body.
There is some suggestion the deceased may be the same man seen jumping off the QE2 Bridge a week ago.
A second call at 4.31pm to reports of a person in the river near Coalhouse Point in East Tilbury is thought to have been a hoax.
Crews conducted an exhaustive three hour search of the water as far as Royal Terrace Pier in Gravesend but nothing was found.
As well as a lifeboat, Port of London Authority harbour launches Patrol and Kew, motorboat Sea Echo and the Kent Police rigid inflatable boat Sea Horse were all deployed.
Shore side and air searches were carried out by two helicopters, coastguard, police and ambulance units.