Virgin Trains reportedly broke its own rules by releasing CCTV footage of Jeremy Corbyn to rebut his claim their service was "completely ram-packed".
The train company released CCTV stills to the media showing the Labour leader finding a seat on the train, saying it "clearly wasn't the case" he could not find somewhere to sit.
However, releasing the images was in breach of the company's own policies, an internal document released to The Guardian suggests.
The document states CCTV images are only to be made available to the media in two situations: when it is "necessary to seek assistance from the public in connection with a criminal investigation" or to improve the "safety of the railway or prevent railway accidents".
The policy, written by Jim Rawcliffe, the company's emergency planning, fire and security manager, adds: “Any such decision to release footage for these purposes will be approved by the head of safety and environment and, where appropriate, following consultation with the relevant police authority.”
Other passengers have disputed Virgin's trains and insist the train was extremely busy.
The Information Commissioner is also looking into a possible breach of data protection rules following release of the CCTV footage.
One image initially released by the company had the faces of some other passengers visible, but was later withdrawn and replaced with a blurred version. Mr Corbyn was identified in all images and his face never blurred.
The Information Commissioner Office’s 2015 guidance on how avoid breaking the data protection law with a CCTV system warns against posting images on the internet or giving them to the media.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies