A passenger has been caught on CCTV camera defacing a door of a Metro compartment with spray paint.

The carrier released the CCTV footage on Wednesday.

The 35-second clip shows a spectacled man, with a backpack in the front, walking towards one of the doors with a can.

He is then seen spraying on the doors from the can. Another still image shows the doors defaced in black ink.

A Metro official said the footage was from June 27. The carrier was “analysing the footage” before making it public, he said.

The alleged defacement happened on a Medha rake on the north-south corridor (Blue Line), said the official.

“It has been observed that door No. 5 of coach No. 4036 of a Metro rake (MR-409) operated on Blue Line has been defaced recently with black spray paint by a commuter. Appropriate step has already been initiated to identify the offender. We will take legal action against him,” the carrier said.

“Metro authorities request all passengers to refrain from doing such things on the Metro premises. With the help of CCTV cameras installed in the rakes and stations, such activities can be recorded and offenders can be identified. Legal action will be initiated against any person found to be engaged in such activities,” the carrier said.

The official said: “We are seeking police help. A letter will be sent to the Kolkata Police commissioner.”

A few years ago, the exteriors of another train were defaced. Four persons were arrested in that case, the official said.