Tom Brady has helped Best Buddies raise significant cash, but an investigation finds the developmental disabilities nonprofit has simultaneously funneled millions to the NFL star’s charity.

Best Buddies International, which aims to form friendships between those with and without developmental disabilities, has sent $2.75 million to Brady’s charitable trust since 2011, with another $500,000 promised this year, reports The Boston Globe.

The payments make Best Buddies the single largest benefactor to Brady’s Change the World Foundation Trust, which supports the athlete’s high school alma mater, other football player’s charities and the schools his children attend, among other causes, according to the newspaper.

At the same time, Brady has helped raise $46.5 million for Best Buddies since 2001, the group said.

“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,” Best Buddies’ founder and chairman Anthony K. Shriver told The Boston Globe. “It has been super beneficial to us and him.”

Nonprofits are allowed to donate to other nonprofits and experts told The Boston Globe that there’s likely nothing illegal about the flow of funds from Best Buddies to Brady’s group, though they expressed concerns about limited transparency surrounding the relationship.