LONDON — His walk for charity at the age of 99 captivated a nation in the grip of the coronavirus pandemic. But the legacy of Captain Tom Moore, the decorated British army officer who raised nearly 40 million pounds, or $50.5 million, for the National Health Service, has been tarnished by disclosures about how his family profited from the sudden fame of their plucky patriarch.

On Thursday, Britain’s Charity Commission said in a damning report that Moore’s daughter, Hannah Ingram-Moore, and her husband, Colin, had “damaged public trust” with “serious and repeated instances of misconduct” relating to a charitable foundation set up in the name of Moore, who died in 2021.

The couple held on to an advance worth close to $1.9 million for three books by Moore, rather than giving a portion of it to the foundation as they had signaled they would. They used the foundation’s name to obtain approval to build a spa and pool facility next to the Moore family home in Bedfordshire (they were later ordered to tear it down).

And Ingram-Moore had been “disingenuous” when she claimed in interviews that she had never been offered a six-figure salary to become chief executive of the Captain Tom Foundation. She had discussed a salary of $188,000, applied for one of $125,000, and was rejected by the commission.

“Captain Sir Tom inspired a nation and reminded us what service to others can achieve even in the most challenging of times,” David Holdsworth, the chief executive of the Charity Commission, said in a statement. “Sadly, however, the charity set up in his name has not lived up to that legacy of others before self, which is central to charity.”

“We found repeated instances of a blurring of boundaries between private and charitable interests, with Mr. and Mrs. Ingram-Moore receiving significant personal benefit,” Holdsworth said.

Ingram-Moore, who now operates a brand marketing and coaching business, did not respond to a request for comment.

The 35-page report is a tawdry coda to Moore’s story, which began in early 2020 when Ingram-Moore watched her father respond to a broken hip by buying a treadmill to speed his recovery. Moore also took to walking on his spacious brick patio, and his son-in-law offered to pay him 1 pound per lap if he completed 100 laps by his 100th birthday.

Ingram-Moore suggested posting his campaign on an online charity service to try to raise 1,000 pounds for the NHS, then struggling under an influx of coronavirus patients. Within weeks, Moore had raised tens of millions of pounds, becoming a folk hero in a country desperate for a good-news story amid grinding lockdowns and daily death tolls.

“How many 99-year-olds have a treadmill and still drive?” Ingram-Moore said in an interview with The New York Times in 2020, explaining how she saw an opportunity to generate publicity from her father’s efforts. “We were not ignorant of that fact, and we will never claim total surprise.”

There is no evidence that any of the funds raised by Moore for the NHS were misused, the commission said, and all the initial donations were given to NHS Charities Together, as promised. But the report said there were persistent questions about a web of ventures and projects that Ingram-Moore and her husband subsequently spun around Moore.

In addition to the book deal with Penguin Random House, which included a memoir, the couple signed deals to market a “Captain Tom limited edition barrel-aged gin” and a “Captain Tom rose” for gardens, with some of the proceeds set to go to the foundation.

From April 2021 until early 2022, the Ingram-Moores operated an online store that sold Captain Tom- themed merchandise. The foundation was to receive 15% of the sales, but the report said the store operated at a loss, and the foundation received only about $1,500.

In June, the commission barred her and her husband from being a trustee of, or senior officer at, any charity — for 10 years in her case, and eight years in his.

In December 2020, Moore and his family took a trip to Barbados, paid for by British Airways, which prompted criticism from some who questioned why a 100-year-old man would vacation overseas at a time when the government was discouraging such travel because of the pandemic.

His defenders pointed out that the trip happened before Boris Johnson, the prime minister at the time, tightened England’s lockdown rules. There is no evidence that Moore became ill on the trip, but he tested positive for COVID-19 soon after his return and died a month later.

Rarely has anyone become an icon as quickly as Moore did. Prince William called him a “one-man fundraising machine,” while Queen Elizabeth II emerged from pandemic seclusion to bestow a knighthood on him at Windsor Castle. Moore recorded a duet of the Rodgers and Hammerstein standard “You’ll Never Walk Alone” with English singer Michael Ball, which went to No. 1 in the charts.

Charming, dapper and spry, Moore was his own best salesman. In interviews, he described his military service during World War II in Burma, now known as Myanmar, where the British army mounted a desperate counterattack on its Japanese occupiers, risking tropical disease and insect bites.