A Customs officer has died after his vehicle fell into the sea from Shenzhen Bay Bridge on Monday night.

Police said they received a report at about 9 pm on Monday of a traffic accident on the northbound route of the Shenzhen Bay Bridge.

At a press briefing, chief inspector Chui Wing-luen said the road was dry and there was no road maintenance work at the scene.

"Officers found two skid marks on the fast lane of the road and a damaged road maintenance sign on the slow lane. There were also signs of impact on the railings. We believed the vehicle plunged off the bridge after the accident," he said.

The Fire Services Department said the diving team took over two hours to locate the vehicle, and rescuers retrieved the driver's body from the car at around midnight.

An assistant divisional officer Yu Wai-wah said conditions weren't favourable for the search and rescue mission.

"The water is shallow and the environment is dark. The visibility is very low underwater, which made the search more difficult," he said.

Police said the driver was sent to Tin Shui Wai Hospital where he was later certified dead.

They said there were no surveillance cameras at the scene, but officers would inspect the vehicle and try and find out how fast it was travelling at the time of the accident.

The Commissioner of Customs and Excise Louise Ho expressed deep condolences over the passing of the officer, who died while heading to work.

She said the man was a senior customs officer stationed at the Shenzhen Bay Control Point.