The Supreme Court on Wednesday threw out a case brought by anti-corruption lawyer Prashant Bhushan that accused Prime Minister Narendra Modi of accepting suspicious cash payments, dealing a blow to opposition leader Rahul Gandhi who had latched on to the case.
A panel of judges found that there was too little evidence to go on, deflating Gandhi's warnings late last year that he would cause an "earthquake" by unveiling proof that Modi was corrupt.
In the event, it transpired that the heir apparent to the leadership of the opposition Congress party was referring to a case already before the highest court that relied on evidence recovered in income-tax raids on two corporate houses.
Citing written records, the plaintiff alleged that an individual called "Gujarat CM" had received cash payments from companies totalling at least 400 million rupees ($5.9 million) in late 2013 and early 2014.
Modi was the chief minister of Gujarat at the time and went on to win election by a landslide in May 2014.
"There is not enough evidence to order an inquiry into the case. We are dismissing it," a Supreme Court bench headed by Justice Arun Mishra ruled.
Attorney General Mukul Rohatgi, the government's top lawyer, told the court that there was no credible evidence to prove that Modi had been paid off.
"Nobody in the country would be safe if such documents are accepted as legal evidence. Anyone can put the name of anybody on such papers," Rohatgi told the court.
Prashant Bhushan, the anti-corruption lawyer who brought the case on behalf of a non-governmental organisation called Common Cause, had urged the court to order a probe into the alleged payments made to public officials. "It is sad and unfortunate that the Supreme Court dismissed my plea," Bhushan told Reuters.
Indian politicians are often dogged by sleaze allegations and many of the country's elected officials face criminal proceedings. Modi has, however, cultivated a clean image as the son of a humble tea seller.
He shook India in November by scrapping high-value banknotes in a bid to purge the economy of "black money" - the proceeds of illicit business, corruption and tax evasion. The move has caused massive disruption to daily life and business throughout the country of 1.3 billion people.