Less than a decade ago, the world’s largest meatpacker was in trouble. The Brazilian brothers who ran it were behind bars, and their company, JBS, had been fined billions of dollars for bribing politicians in one of the biggest corruption cases in history.

Now, JBS, a Brazil-based company with operations around the globe and a huge slice of the U.S. meat market, has made a stunning comeback, even as it faces continuing court cases related to price-fixing, child labor and environmental crimes in the Amazon rain forest.

After years of attempts by JBS, U.S. regulators finally approved a public listing for the firm on the New York Stock Exchange, setting aside concerns about the company’s business and protests from American beef producers, environmental groups and politicians across the political divide.

It is a major victory for JBS that provides it a big flow of capital and an American seal of approval. By trading on the world’s biggest stock market, the company can now reach a large pool of U.S. investors and raise more cash by issuing and selling shares to investors.

But the timing is raising eyebrows. A U.S. firm owned by JBS made the single biggest donation, $5 million, to President Trump’s inaugural committee, and the Brazilian company also doubled its spending on lobbying in the first three months of the year, a New York Times analysis of public records shows.

The donation and subsequent approval of JBS’s listing by the U.S. Securities and Exchange Commission, headed by a new chairman appointed by Mr. Trump as the president reduces the commission’s independence, have fueled concerns from Democrats and watchdog groups that the firm’s gift may have helped it win favor from the administration.