Beijing has stepped up a war of words with the United States as three high-level mainland Chinese agencies accused Washington of smear tactics over Hong Kong’s adherence to the rule of law and its national security legislation after the conviction of media tycoon Jimmy Lai Chee-ying for fraud.

The State Council’s Hong Kong and Macau Affairs Office (HKMAO) said on Thursday Washington’s criticism was “shameless”.

The commissioner’s office of the Chinese foreign ministry in Hong Kong added the US attempt to “whitewash” Lai would bring “disgrace” on the country and the central government’s liaison office in the city condemned the United States for “backing anti-China elements”.

The agencies hit out after the US State Department attacked the decision to convict Lai on Tuesday.

“We remain deeply concerned about the deterioration in protection for human rights and fundamental freedoms and the systematic dismantling of Hong Kong’s autonomy under the national security law,” US State Department spokesman Ned Price said.

“These include increased efforts to wield the national security law to suppress independent media, to silence dissenting views, and to stifle freedom of speech.

“Though Lai’s fraud trial was not on national security law grounds, local authorities nonetheless imposed [the national security law’s] more restrictive legal procedures for this non-[national security law] case.”

But the HKMAO spokesman accused the US of glorification of “a notorious criminal” as a democracy campaigner and of trying to “find excuses to defend” him.

“It is to admit that the US stands with him and is as despicable as him,” he said.

The spokesman added the “statement just rambles on, making excuses to smear Hong Kong’s rule of law and attack the Hong Kong national security law. That is shameless”.

He highlighted Beijing’s pledge that it would continue to block foreign forces’ interference in Hong Kong affairs.

Lai, the founder of the now-closed Apple Daily newspaper, was convicted of fraud over the unauthorised operation of a consultancy firm at its offices in breach of the land lease conditions.

Spokesman Ned Price said the US State Department remains “deeply concerned about the deterioration in protection for human rights and fundamental freedoms and the systematic dismantling of Hong Kong’s autonomy under the national security law”.

The judge called for background reports on Lai and fellow defendant Wong Wai-keung, the former chief administrative officer of Lai’s Next Digital, who was also convicted of fraud.

The court will hear pleas in mitigation on November 24 before sentence is passed.

The commissioner’s office condemned the US for “hyping up Jimmy Lai’s fraud case”.

“No one is above the law no matter what their background or what forces are behind them,” a spokesman said.

“The evidence is irrefutable in Jimmy Lai’s fraud case and it’s a statutory duty for Hong Kong courts to try the case in accordance with the law, which safeguarded Hong Kong’s rule of law, has nothing to do with freedom of the press and speech, and brooks no interference.”

The spokesman said the US had “repeatedly trampled on international law and the basic norms governing international relations and meddled in Hong Kong affairs and China’s internal affairs”.

“What the US side has done is a gross violation of both Hong Kong’s and international rule of law,” he said.

The spokesman added that “during the 2019 turbulence, Jimmy Lai openly clamoured for ‘fighting for the United States’”.

“History has shown, and will continue to prove, that no intervention can stop the historical trend of Hong Kong moving to greater prosperity and the great rejuvenation of the Chinese nation,” the spokesman said.

A spokesman for the central government’s liaison office in Hong Kong accused the US of turning a blind eye to the “crimes” that anti-China elements had committed and of interference with the country’s internal affairs and Hong Kong’s rule of law.

The Hong Kong government earlier blasted the US, and said its criticisms over Lai’s fraud case were “purely politically oriented”.

“Foreign politicians who deliberately turn a blind eye to the reasons for the court’s verdict and make unfair and biased comments on the court’s verdict based merely on the outcomes of cases that are not in line with their political interests not only reveal their ignorance, cowardice, unfairness, arrogance and disregard of the law, but also make their attempts futile,” a government spokesman said.

He added: “As a matter of fact, since the implementation of the Hong Kong national security law, Hong Kong has moved from chaos to stability, and is steadily heading from stability to prosperity.”

A group of US senators issued a joint statement on Tuesday that said Lai’s conviction was a “sham” and praised him as a “strong advocate for press freedom and democracy”.

Lai was last year sentenced to a total of 20 months in jail for his roles in four unauthorised assemblies.

He is at present on remand in jail awaiting a trial for collusion under the 2020 Beijing-imposed national security law.

The legislation prohibits acts of secession, subversion of state power, terrorism and foreign interference.