Indian Prime Minister Narendra Modi's party on Monday made public his university degree certificates, in a bid to disprove allegations by a political opponent that he had fabricated his qualifications.

Since winning an election in the Indian capital last year, Arvind Kejriwal, the ambitious chief minister of the Delhi regional government, has stepped up his attacks on Modi.

Kejriwal has not said why Modi would want to claim a fake degree but the allegations, which set off frenzied speculation on social media, struck a nerve in the prime minister's Hindu nationalist party, upset about the risk to his reputation.

Modi has often cited the journey from his humble beginnings as a tea vendor's son to national leader to win support from the country's poor. Having a degree fits the narrative of a man with the grit and determination to succeed.

Senior leaders of the Bharatiya Janata Party (BJP) held aloft what they said were Modi's degrees, a Bachelor of Arts from Delhi University and a Master of Arts in Political Science from Gujarat University.

"It is very unfortunate that we have to clarify the prime minister's educational qualification," party president Amit Shah told a news conference in New Delhi at which he was flanked by Finance Minister Arun Jaitley.

Spokesmen for the two universities declined to comment on whether Modi's degree certificates were genuine.

Kejriwal says he has evidence Modi misappropriated the degrees of someone with the same name.

A spokesman for Kejriwal's party stood by the accusations, saying there were inconsistencies in the dates and names on Modi's degrees.

"We are happy to have an illiterate prime minister," said the spokesman, Vikas Yogi. "But not a prime minister who lies about his degrees."

Modi's party distributed photocopies of the certificates to journalists, with its officials saying Kejriwal should apologise to the country for doubting Modi's credentials.

"The degrees are in the public domain, but such allegations debase our political discourse," said party president Shah.

Kejriwal, a self-styled anti-graft crusader, has been at loggerheads with the BJP since last year.

In December he accused Jaitley of allowing fraud at a cricket association that he ran for a decade from 2003. Jaitley has denied any wrongdoing and sued Kejriwal for 100mn rupees ($1.5mn) for slander.