HONG KONG — When the Twitter account of a Chinese ambassador on Wednesday “liked” a tweet of an X-rated video involving the use of feet, a furious statement from the Chinese Embassy demanded that Twitter launch an investigation.
The like created a storm on social media, with many debating whether it had been an accident or if the account of the ambassador to Britain, Liu Xiaoming, had been hacked.
Evidence suggests that Mr. Liu may be a tech-unsavvy boomer struggling to master a platform that is banned in his own country. The account has a history of odd likes. It has frequently liked its own tweets. It has even liked criticism of China itself.
But the episode threatened to become an embarrassing marker in the tenure of a leading voice among China’s “wolf warrior” diplomats.
A Twitter representative declined to comment on Thursday about China’s demand for an investigation.
As the controversy boiled over, the ambassador’s account quickly scrubbed all but two of the dozens of likes it had accumulated over the past year, including the one for the video.
But the tabloids in Britain — whose diplomatic ties with China have grown more strained over the national security law imposed by Beijing on Hong Kong, a former British colony — immediately seized on the Twitter storm.
The Sun tabloid screamed that the “Firebrand Chinese Ambassador” had “PUT HIS FOOT IN IT.”
Mr. Liu, 64, one of China’s most high-profile diplomats, has served as the ambassador to Britain since 2009. He frequently appears on television attacking China’s critics and batting away criticism of his country’s crackdown on democracy advocates in Hong Kong and its mass incarceration of Uighurs in the Xinjiang region.
On a BBC program in July, he was shown drone video, apparently of prisoners in Xinjiang being led onto a train. When asked what was happening, he struggled to answer, then replied, “Xinjiang is regarded as the most beautiful place.” He later suggested that the video could be fake.
Mr. Liu joined Twitter last year after other Chinese diplomats had amassed large followings on the site. He quickly adopted the aggressive tone of some of his colleagues, who have been nicknamed “Wolf Warriors” after the popular Chinese film series. In less than a year, his following grew to more than 85,000.
He has used Twitter to attack Adrian Zenz, a scholar who has researched the Xinjiang crackdown. He has accused external forces of fomenting the protest movement in Hong Kong last year. He has praised China’s coronavirus response and defended Huawei, the embattled Chinese tech company.
But from the time he joined the social media platform, the like function has proved particularly troublesome.
Soon after his account posted an introductory message in October (“Hello Everyone! I’m Liu Xiaoming…”) his account liked a reply that a Chinese ambassador wouldn’t normally approve: “Hail China dictatorship man! Hail totalitarianism!”
The loose likes did not appear to become a serious issue until Wednesday, when Mr. Liu’s account attained infamy.
“WARNING: DO NOT READ THIS IF EATING,” Luke de Pulford, a member of the British Conservative Party’s Human Rights Commission, wrote in a tweet drawing attention to Mr. Liu’s apparent endorsement of the video. “Felt a bit mean for this,” Mr. de Pulford added. “But then I remembered the #Uyghur concentration camps and #HongKong and quickly got over it.”
The Chinese Embassy quickly came to Mr. Liu’s defense, blaming unnamed “anti-China elements” who it said had “viciously attacked Ambassador Liu Xiaoming’s Twitter account and employed despicable methods to deceive the public.”
“The Embassy has reported this to Twitter company and urged the latter to make thorough investigations and handle this matter seriously,” the statement continued. “The Embassy reserves the right to take further actions and hope that the public will not believe or spread such rumour.”
Mr. Liu joined a group of officials around the world who have been tripped up by strange or inappropriate tweets.
Anthony D. Weiner, a Democrat from New York, resigned from Congress in 2011 after he tweeted an explicit photo of himself and later admitted to having inappropriate relationships with women online while married. Ed Balls, a former member of Parliament in Britain, tweeted his own name in 2011, apparently while trying to do a search. (The date on which he did so, April 28, is now known as Ed Balls Day on Twitter.) And the account of Senator Ted Cruz, the Texas Republican, liked a pornographic tweet in 2017, which was blamed on a staff member.
Mr. Liu has not directly addressed the controversy. But he tweeted an obscure maxim that appeared to declare his innocence: “A good anvil does not fear the hammer.”