British Transport Police (BTP) have issued a CCTV still image of a man they wish to speak to in connection with an alleged hate crime attack on a Polish woman on a London Underground train.
The man is said to have started an argument with the woman on a District Line train, before punching her so hard in the face she fell to the ground. He then alighted at Hammersmith.
The incident took place on a westbound train just after midnight on 22 August 2016. The incident is being treated as a potential hate crime because the man referred to the woman's nationality before attacking her and escaping.
BTP Investigating officer Det Con Denis Mahoney said: "Violence and hate crime have no place on our transport system and we are committed to stamping them out. Behaviour of this kind is completely unacceptable and so I urge anyone who recognises this man to get in touch with us."
The alleged attack took place two months after the UK voted to leave the European Union, following which there was a rise in reported hate crimes.
The UK's large Polish community has often been targeted, and five days after the District Line attack Pole Arek Jozwik was attacked and later died in what appears to have been a hate crime in Harlow, Essex.
A Polish community centre was vandalised days after the Brexit vote on 23 June, while anti-Polish leaflets handed out in Huntingdon. Hate crimes are reported to have risen by 42% in June compared to 2015. Deputy Commissioner Craig Mackey said it appeared the Brexit vote had "unleashed something in people."
Following Arek Jozwik's death, new Prime Minister Theresa May told Polish counterpart Beata Szydlo that "hate crime has no place in UK society." A Hate Crime Action Plan has now been put in place by the government.
Anyone with information about the District Line attack is asked to contact British Transport Police by calling 0800 40 50 40 or texting 61016, quoting 235 of 02/11/2016.