Hong Kong's new electronic auto-toll system will come into operation at the Eastern Harbour Crossing on Sunday.

The crossing will be the last of the city’s three cross-harbour tunnels to implement to HKeToll system.

From 5am on Sunday, motorists will no longer have to stop at booths to pay their tunnel tolls.

The charge will be deducted automatically for drivers with a registered electronic tag in their vehicle, while others will be sent a bill.

The Transport Department said the tunnel will be closed off to traffic from 4 to 5am to facilitate transition to the new system.

"We are doing a lot of arranging works including the temporary traffic, and [we] advise the drivers follow the traffic sign road marking along the toll plaza," deputy transport commissioner Patrick Ho said.

Officials also warned members of the public to watch out for fraudulent messages requesting for tunnel toll payments.

“I would like to emphasize that we won’t send out text messages or emails with hyperlinks,” principal transport officer Albert Ho said.