India's top court has sentenced a controversial sitting judge to six months in prison after he was found guilty of contempt. Calcutta High Court Justice Chinnaswamy Swaminathan Karnan was ordered to be sent to jail on Tuesday (9 May) for allegedly making scandalous remarks against his fellow judges.

It is believed to be the first time in Indian judicial history that a sitting judge has been sentenced to a prison term. The court has asked police in the eastern Indian state of West Bengal to arrest him immediately. But Karnan is reported to have travelled from Kolkata to his hometown Chennai, south India, on Monday night.

Karnan has had a months-long face-off with the judges of the Supreme Court, following which he was stripped of his judicial powers earlier in February.

The Supreme Court in its verdict on Tuesday described Karnan's confrontation with his colleagues as the "gravest of all" and said he had "abused the judicial powers and the discretion". It has also banned media from publishing or broadcasting Karnan's comments.

The controversy began when Karnan wrote a letter to Prime Minister Narendra Modi in January requesting him to order an investigation against his fellow judges at the Madras High Court, where he was serving at that time. He also wanted a probe into corruption allegations against the apex court.

In February, the Supreme Court had ordered him to explain his allegations with evidence, which Karnan failed to provide. He still urged Modi to investigate and take action against some 20 judges he claimed were corrupt.

He was eventually issued a bailable warrant in March and barred from performing any judicial or administrative duties.

Karnan, however, rejected the warrant and accused the Supreme Court judges of caste discrimination. He even banned seven judges from travelling out of the country.

The events followed a string of tit-for-tat orders between Karnan and the apex court, with the former reportedly remaining defiant throughout.

Earlier this month, a seven-judge Supreme Court bench, which included the Chief Justice of India J S Khehar, ordered a medical evaluation for Karnan. But the 61-year-old refused to comply and angrily responded by ordering similar tests for the seven judges.

On 8 May, Karnan took an unprecedented step by sentencing Khehar and the other judges of the apex court to a five-year jail term. His order alleged the judges were guilty of discrimination.