New England Patriots quarterback Tom Brady has used his superstardom to boost one of his pet charities, and it, in turn, has helped his with significant contributions, according to a detailed account by the Boston Globe.

Brady has for years had a relationship with Best Buddies International, a nonprofit organization founded to help intellectually and developmentally disabled people, and has participated in an event with the group in the summer. Along the way, he has helped Best Buddies raise over $20 million over the last six years, the Globe’s Bob Hohler reports, with Best Buddies paying $2.75 million to Brady’s Change the World Foundation Trust. In addition, it has pledged another $500,000 in 2017.

Brady, whom the Globe says is the only trustee of his private charity, initially funded it with a $490,000 donation in 2005 and has not made a significant financial contribution according to tax reports through 2015. Through 2015, the last year for which records are available, Best Buddies has supplied “nearly 98 percent of Change the World’s total contributions of $2.3 million since Brady’s initial donation were $2.25 million in grants from Best Buddies. Including Brady’s donation, the percentage is about 80 percent,” Hohler writes.

Brady has an estimated personal worth of $180 million, while his wife, supermodel Gisele Bündchen, is worth an estimated $360 million. According to independent charity watchdogs contacted by the Globe, it appears that there is nothing illegal with the arrangement. “It is not unusual for nonprofits to pay celebrities to help raise money,” one unnamed watchdog told the Globe, “and they did not dispute that Best Buddies has realized an enviable return on its relationship with Brady.” There is some question, though, whether Best Buddies should report the payments as fundraising expenses and not charitable gifts.

“I think it has been a smart move, because we have been able to provide services to tens of thousands of people because of Tom, while keeping him engaged and helping him pursue some of his own interests,” Anthony K. Shriver, the Best Buddies founder and chairman, told the Globe, adding that there is no contract with Brady and that he is just expected to donate $500,000 annually to Brady’s trust. “It has been super beneficial to us and him.”

Where does the money in the Change the World Foundation Trust go? Junipero Serra High School, Brady’s alma mater in San Mateo, Calif., received $250,000, the largest donation of the nearly $1 million given to 30 nonprofits from 2011 through 2015. The next largest grants, of $100,000 each, went to St. Monica Catholic Community in Santa Monica, Calif., where Brady and Bundchen were married, and the TB12 Foundation, formed by Brady in 2015 to support clients of his TB12 fitness and nutrition company.

It also has donated to charities headed by some of Brady’s teammates, as well as to private schools attended by Brady’s children.

Brady has not commented other than to say in a release by Best Buddies: “This organization has become a part of my life. I love meeting the inspiring buddies at events, seeing their smiles, and hearing them talk about how Best Buddies has changed their lives for the better by helping them make friends at school and find meaningful jobs in their local communities. Best Buddies’ mission is a simple one, but the impact is incredibly powerful. I am so grateful to be a part of this global movement.”

The arrangement was born out of the friendship between Brady and Shriver, who founded the organization in 1989. His late mother, Eunice Kennedy Shriver, founded the Special Olympics, and the cause has long been supported by the Kennedy family. Shriver told the Globe that, after volunteering his time and image to Best Buddies for years, Brady increasingly wanted to focus on his own foundation.

Shriver told the Globe that he recalled Brady saying before payments began in 2011, “When I come to Best Buddies events, it’s all about Best Buddies, which is the way I want to keep it while I develop my interests. Would you support helping me pursue my things while I continue to put a lot of energy into your thing?’ ”