MTR Corp has launched an internal probe to understand how an Airport Express train was switched onto the Tung Chung line.

A Hong Kong-bound Airport Express train was leaving Kowloon station at 9:25 yesterday morning when an operations control centre staff member noticed it was set to arrive at the Tung Chung line platform at Hong Kong Station.

The staffer instructed the driver to stop the train and then reset the train route to the Airport Express platform, HK01 reported.

The incident caused a delay on the Tung Chung Line, but otherwise did not affect the safe operation of the trains, MTR said.

The company apologised for the incident and is conducting an internal investigation. It is preparing a report for the Transport Department.