Lists of donors and beneficiaries cast government contracts and police investigations in an unflattering new light.

Politics in India is an expensive business, and sometimes lucrative, too. In this year’s election, parties are expected to spend more than $14 billion — as much as in the United States. But there has been little in the way of transparency for the huge sums sloshing around.

On Thursday night, a rare and chaotic beam of light shot through the darkness. By order of India’s Supreme Court, the government-owned State Bank of India handed reams of data to the election commission, showing who had directed cash to the country’s political parties through a mechanism known as electoral bonds.

Reading between the lines of the spreadsheets full of names poses questions about the intersection of government and business in India. Construction companies, gambling impresarios, pharmaceutical bosses and many more corporate entities and individuals had forked over $1.7 billion in bonds since 2019. Many ended up winning government contracts. Most had faced trouble with the federal police.

Jairam Ramesh, a leader of the opposition Indian National Congress party, said a clear picture had emerged: that the ruling Bharatiya Janata Party of Prime Minister Narendra Modi used law enforcement agencies to extort businesses into filling its coffers.

“In my view, this is independent India’s biggest scandal,” Mr. Ramesh said. The way the country’s top law enforcement and financial crime agencies had “been used to terrify people,” he added, “it has never happened before.”

Mr. Ramesh’s party has deposited electoral bonds, too, worth at least $170 million. But Mr. Modi’s B.J.P., which controls both the budget and the federal agencies, has received nearly four times as much since 2019, more than the next six parties combined.

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The full reach of this data dump will take days if not weeks to parse. In the meantime, election season is hitting a fever pitch. On Saturday, the voting dates will be announced; they are likely to stretch from April into May.

Electoral bonds are just one avenue for campaign finance, but they have attracted more attention than any other since the B.J.P. introduced them nearly seven years ago.

Perhaps the most striking thing about the list of donors is the names it does not include. The Adani Group, the giant conglomerate whose value has grown by almost 1,000 percent since Mr. Modi took power, appears nowhere. Mukesh Ambani, Asia’s richest man, does not either, although his Reliance Industries has a roundabout connection to the third-largest donor listed.

Directors on the board of Qwik Supply Chain, which bought about $50 million worth of electoral bonds, sit on the boards of Reliance companies. Reliance released a statement saying that Qwik Supply “is not a subsidiary of any Reliance entity.”

The biggest buyer was a company called Future Gaming and Hotel Services, which snapped up $165 million in bonds. That is many times greater than the profits it has reported in any year. The company’s owner, Santiago Martin, often styled as India’s “lottery king,” was under investigation for money laundering. He was also locked in a dispute with the state of Tamil Nadu, which tried to ban gambling — only to be thwarted by the national government.

Ironically, the electoral bonds system was promoted as a means to bring legitimacy to a hodgepodge of mostly illegal funding practices that all parties had been using for decades. Donors would buy bonds from the state bank anonymously and then pass them on to politicians. Critics complained immediately that this process only formalized secrecy.

Mr. Modi’s government had come to power in 2014 on the back of a series of financial scandals that humbled his predecessors. Then an anti-corruption campaign boosted his campaign. Yet any revelations now cannot be expected to generate widespread protest. The Indian media is reliably supportive of Mr. Modi’s government.

Democracy activists had petitioned the country’s top court in 2017 to declare the new fund-raising model unconstitutional, on the grounds that it lacked transparency and denied a level playing field to different parties.

“The whole idea for anonymous donations was to make money, to get kickbacks, anonymous kickbacks. Clearly, almost everything is a kickback,” said Prashant Bhushan, one of the lawyers who brought the case against the government.

Jagdeep Chhokar, an activist who petitioned the court, said that with Thursday’s data release, the bank authorities still had not revealed the “granular details” — for example, “which company has donated exactly how much money to which party exactly on what date.”

Since the day the policy was framed, Mr. Chhokar said, he and other activists have been arguing “that this is the way to legalize something which is patently wrong.”

Nirmala Sitharaman, the government’s finance minister, dismissed any allegation of quid pro quo, saying that there was nothing to establish a link between raids by investigative agencies and funding, and that any such charges were mere “assumptions.”

“Was the system before this 100 percent perfect? No,” Ms. Sitharaman told an Indian television channel. “This is certainly not perfect, but one bit better.”

Electoral bonds as a mechanism may go away after the Supreme Court’s decision against them a month ago, but their story is not yet over. On Friday, India’s chief justice issued another directive to the State Bank of India. Why, he asked, has it failed to provide the bonds’ identifying numbers, which would establish which political group received funds from where?

“The judgment of the constitution bench clarified that all details of electoral bonds will be made available including date of purchase, name of purchaser, the denomination,” the judge, Dhananjaya Yeshwant Chandrachud, wrote. He ordered the bank to fill in the missing facts by Monday.

Sameer Yasir and Suhasini Raj contributed reporting.

Excerpts: The New york Times