The UK embassy said Liu Xiaoming's account had been "viciously attacked" and reserved the right to take further action after the account 'liked' a pornographic video and several tweets criticising the Chinese government.
The 'likes' remained active for around an hour before they were 'unliked', after which a spokesman for the UK embassy released a statement condemning the "hack".
The spokesman said: "Recently some anti-China elements viciously attacked ambassador Liu Xiaoming’s Twitter account and employed despicable methods to deceive the public.
"The Chinese embassy strongly condemns such abominable behaviour.
“The embassy has reported this to Twitter company and urged the latter to make thorough investigations and handle this matter seriously.
"The embassy reserves the right to take further actions and hope that the public will not believe or spread such rumour.”
Liu reposted the tweet, adding: “A good anvil does not fear the hammer.”
Twitter is banned in China but many of the country's diplomats abroad use have accounts. Liu's account, which has more than 85,000 followers, usually shares content that is favourable to China.
Twitter has been contacted for comment.