A train expert says the MTR Corporation may need to improve its checking of trackside equipment, following Sunday's partial derailment of a train at Yau Ma Tei.

On Monday, the MTRC suggested the train may have hit a component that had come off a metal barrier next to the track.

Noting that media reports suggested the obstruction was the cover from a tunnel ventilation fan, Henry Cheung, who is chairman of the Association of Hong Kong Railway Transport Professionals, told an RTHK programme this seemed to have been missed in manual checks.

"In normal circumstances, anything mounted on the trackside would be secured and checked by maintenance staff, so it looks like this time they may have missed something," he said.

Cheung added that while the incident was rare, it was the second similar accident within a year, after a trackside advertising panel came loose and hit a train in Causeway Bay last December: "The MTR needs to look into this," he said.