Transport chiefs have launched in investigation following claims that a London Underground worker was seen watching pornography at Wembley Park station.

According to a shocked commuter the man was watching the x-rated film on his tablet as he supervised busy platform.

He told the Sun newspaper: “On Wednesday I was at Wembley Park station when I saw the platform supervisor sitting in his cab intently viewing a tablet.

“On closer inspection I noticed it was porn, and he continued to watch it even when a train came into the platform.”

He added: “I could clearly see it was a Japanese film involving a man and a woman. I asked him a question, he held the device to his chest and then continued to watch it as I walked away.

“He didn’t look shocked at all – he acted like it was a completely normal thing.”

A spokesman for Transport for London said: “Any conduct of this nature is totally unacceptable.

“An immediate investigation is underway and the appropriate action will be taken.”