The documentary, which focused on Modi’s leadership as chief minister of the western state during riots in 2002 in which at least 1,000 people were killed, most of them Muslims. Activists put the toll at more than twice that.

Afghan Voice Agency (AVA) - Monitoring: Modi has denied accusations that hedid not do enough to stop the riots and a Supreme Court-ordered investigation found no evidence to prosecute him.

The suit was filed on the basis that the documentary “casts a slur on the reputation of the country” and “makes false and defamatory imputations and insinuations” against its prime minister, judiciary, and criminal justice system, the court order said.

The court sought a response from the broadcaster by September 25.

A BBC spokesperson said: “We are aware of the court proceedings. It would be inappropriate to comment further at this stage.”

Relations between India and Britain have soured after the documentary and a “breach of security” incident at the Indian High Commission in March, at a time when they are struggling to make progress in free trade talks.

India reacted angrily to the documentary, which aired in January, calling it a biased “propaganda piece” and blocking sharing of any clips from it on social media.

Tax officials inspected offices of the BBC in Delhi and Mumbai in February and the financial crime agency opened an investigation into the broadcaster in April for alleged violations of foreign exchange rules.

The tax authority had said that it found evidence of undisclosed income in the records of an “international media company” without naming the BBC. A government adviser said the inspection was not “vindictive”.

The BBC has previously said that it stood by its reporting for the documentary, which was not aired in India, and that it “does not have an agenda”.