Not long after, Ms. Carter was hired by FreshDirect to make the company’s case to the community.

The story of Majora Carter, 46, is one of the best known in the South Bronx. The youngest of 10 children, she grew up in Hunts Point and later emerged as a fierce defender of its residents against urban blights like truck traffic and garbage dumps. Smart and passionate, with a high-wattage smile for the cameras, Ms. Carter was soon touring the Arctic with former President Jimmy Carter, hosting a Peabody-winning public radio show, and commanding tens of thousands of dollars in speaking and consulting fees.

Ms. Carter’s meteoric rise also made her a polarizing figure. Many former allies and neighbors say that Ms. Carter trades on the credibility she built in the Bronx, while no longer representing its interests. They say she has capitalized on past good deeds in the way that politicians parlay their contacts into a lobbying career, or government regulators are hired by the companies they once covered.

“You can’t have it both ways,” said Eddie Bautista, executive director of the New York City Environmental Justice Alliance. “Either you’re an honest broker and accountable to the community, or you’re working for a business interest and accountable to that.”

In a phone interview, Ms. Carter insisted that she had never stopped working to support the South Bronx. She said she would have supported FreshDirect even if she was not paid, saying that she had never been anti-business and that the company would create jobs, provide access to healthy foods, and promote local food-based businesses. “I thought that ultimately they would be able to provide a net benefit to the community,” Ms. Carter said.

She addressed the criticism by ticking off some of her many honors and noting her status as a “thought leader.” Her husband, James Chase — who tends to Ms. Carter’s public image as a vice president of her consulting firm — called charges that she was financially motivated “revolting.” Nothing has highlighted the division over her legacy like the continuing battle over FreshDirect. The planned opening of a new headquarters for the company in the Bronx escalated from a not-in-my-backyard campaign to an acrimonious debate over how to help an area struggling with high rates of unemployment, obesity, diabetes and asthma.