An Indian court has sentenced a journalist to one year in jail for some of his social media posts on the Adani Group, saying they were unverified, defamatory and portrayed the group in a disreputable light.

Adani Enterprises, led by billionaire Gautam Adani, filed the case in 2021 against India journalist Ravi Nair in a district court in Gujarat, accusing him of making statements suggesting "political patronage... financial irregularities and unethical conduct", according to a Tuesday court order seen by Reuters.

"No documentary material, official record, or verified data has been produced to substantiate the serious allegations made against the complainant company," the court said in its order.

Nair told Reuters he will appeal the conviction but declined to comment further.

The Adani group did not immediately respond to a Reuters request for comment.

Nair's lawyer argued the posts were based on publicly available material and constitute fair comment and criticism, the court order noted.

India is among those countries where criminal defamation is still part of the legal system and carries a maximum jail term of two years.

The law has previously faced opposition from lawyers, journalists and activists, including an unsuccessful legal challenge before India's top court in 2016.

Press freedom group Committee to Protect Journalists said it was "deeply concerned" with the verdict.

"We are closely monitoring the situation," it said on X.