According to the New York Times, investigators are looking for evidence of potential money laundering and election fraud. They reportedly want documents about the committee’s donors, the benefits given to those donors, and the committee’s vendors and contracts. The committee raised a record-breaking $107 million for Trump’s inauguration.

The paper said the subpoena indicated the Manhattan Attorney’s Office prosecutors wanted documents relating to Stripe. Previous reports have noted that Stripe was the payment processor used by Trump’s presidential campaign. Indeed, many candidates, including Hillary Clinton, used it to support their donation systems.

Stripe co-founder John Collison noted in 2015 that use of the platform meant campaigns didn’t need to hire people to handle donations and payments.

There’s no suggestion that Stripe did anything wrong here—it’s a widely-used payments processor. At this stage, its mention in the subpoena simply means that it might have information pertinent to the prosecutors’ investigation. But in this case, there’s another notable aspect: one of Stripe’s big investors is Thrive Capital, the founder and managing partner of which is Josh Kushner. Josh Kushner, who was apparently not named in the subpoena, is the brother of First Son-In-Law Jared Kushner.

Trump’s inaugural committee has long been a focus for Special Counsel Robert Mueller, whose team questioned Russian oligarchs to find out if they made illegal donations to the committee and the campaign before it. According to the Washington Post, it’s not clear if Mueller is still pursuing the inauguration angle or if the subpoena indicates he referred the matter to prosecutors in Manhattan.

Fortune has asked Stripe for comment, and will update this story when it arrives.