SHANGHAI (REUTERS) - Chinese prosecutors have filed a lawsuit against an individual accused of insulting a fireman who died in the line of duty, the first such case since the country adopted a law in April that bans the defamation of heroes and martyrs, state media said.

President Xi Jinping has ushered in several laws in the name of protecting China and the ruling Communist Party from perceived threats both internal and external, as well as presiding over a crackdown on dissent and free speech.

The procuratorate of the eastern province of Jiangsu filed the public interest case on Monday (May 21), the influential Global Times tabloid said online.

A person it identified only by the surname Zeng had"allegedly spread hate speech" on social media against Xie Yong, a fireman who fell to his death from a building during a rescue operation on May 12.

The law makes it illegal to "misrepresent, defame, profane or deny the deeds and spirits of heroes and martyrs, or to praise or beautify invasions," state media said in a summary when it was introduced.

Anyone infringing it faces punishment in line with the law and may be investigated for criminal responsibility.

In its report late on Monday, the Global Times said Xie was declared a martyr a day after his death in heavy smoke, after he left his respirator with a colleague.

It said Zeng had been placed in criminal detention after posting comments in WeChat groups. Reuters was unable to trace contact details for Zeng or a representative to seek comment.

The Communist Party has long kept a tight grasp on its history, bolstering its legitimacy with tales of heroes and martyrs who gave their lives to the party's causes.

Disputing party history and questioning the deeds of heroes have already landed some historians in court.