Facebook is in the eye of a political storm in India after claims it failed to take action against hate speech posts by a Hindu nationalist lawmaker out of fear for its business interests.

India is US-based Facebook and its messaging service WhatsApp's biggest market in terms of users, and the firm is under pressure worldwide about how to police hate speech.

But a huge row has now erupted in India after the Wall Street Journal reported that Facebook stopped short of banning a ruling party MP even after he posted comments and made speeches saying Rohingya Muslim immigrants should be shot, Muslims were traitors, and threatened to raze mosques.

The lawmaker in question, T. Raja Singh, on Monday claimed his account had been hacked, the New Indian Express reported.

The Wall Street Journal report last week said Facebook's top public-policy executive in India had opposed applying hate-speech rules to the lawmaker and other Bharatiya Janata Party (BJP) individuals and allied groups who had been flagged internally.

The executive, Ankhi Das, told staff members that punishing violations by politicians from India's ruling party would damage the company's business prospects in India, the newspaper reported.

India is Facebook's biggest global market in terms of users
India is Facebook's biggest global market in terms of users AFP / Olivier DOULIERY

This was even after employees concluded Singh had violated its rules, the Journal said, citing current and former Facebook staff.

The main opposition Congress party on Sunday claimed there was "bias and alignment" of the Facebook India team in favour of the BJP and its allies.

"They spread fake news and hatred through it and use it to influence the electorate," tweeted senior party figure Rahul Gandhi.

Without commenting directly on the Journal report, Facebook said Monday it would always prohibit "hate speech and content that incites violence", and would "enforce these policies globally without regard to anyone's political position or party affiliation".

"While we know there is more to do, we're making progress on enforcement and conduct regular audits of our process to ensure fairness and accuracy," a spokeswoman added.

Lawmaker Raja Singh insisted Monday that his Facebook account had been hacked and someone was "deliberately trying to project me as a dangerous person all over the world."

"Many pages and IDs are being run on my name on social media platforms without my consent," he told the New Indian Express.