The Blackwall Tunnel has reopened more than two hours earlier than expected after it was closed following an asbestos spill.
Both lanes of the Blackwall Tunnel are now open
The northbound carriageway through the tunnel closed at 1230 BST on Wednesday after two 20kg bags containing brown asbestos fell from a van.
Cleaners worked through the night to clear the spillage, allowing the tunnel to reopen before 0900 BST.
The tunnel opened shortly after air quality tests were carried out.
The southbound tunnel remained open as normal.
A Transport for London spokesperson said: "We are pleased to report that, following all night work by Transport for London staff and specialist contractors, the Blackwall Tunnel is open in both directions this morning."
He said that because the Blackwall Tunnel is always busy in the morning and evening rush there may be some "residual delays".
TfL said it is now focusing on identifying the vehicle and driver responsible for dropping the asbestos on to the carriageway of the tunnel.
"Not only was this driver reckless in failing to secure the load but they also failed to stop at the scene of the potentially very serious incident," said the TfL spokesperson.