For uninsured people at risk of HIV, the announcement last month that the U.S. Centers for Disease Control and Prevention had secured an annual donation of more than 2 million bottles of the HIV prevention drug Truvada for PrEP likely came as welcome news.

For many, paying out-of-pocket for the $2,000 per month drug is unaffordable.

President Donald Trump touted the donation as a step towards ending the HIV epidemic for good.

But some public health experts balked. They asked the CDC to enforce its own patents on the HIV prevention drug, which was discovered with the use of federal research dollars. They called for Gilead, the drugmaker that sells Truvada for PrEP, to pay royalties and lower the price.

Now Democrats on the Oversight Committee — Chairman Elijah Cummings along with Reps. Alexandria Ocasio-Cortez, Ayanna S. Pressley and Ro Khanna — want to know whether there was a sweetheart deal between the CDC and Gilead.

In a letter to Gilead CEO Daniel O’Day dated Wednesday, the Oversight Committee requests documents and emails between the CDC or any other federal agency and the drugmaker about the donation of Truvada announced last month. It also seeks documents and emails about any discussion between government health agencies and Gilead about any patents held by the government on Truvada.

The committee is “seeking to understand if the company’s donation of Truvada was in any way connected to patents that have been registered in the United States,” the letter reads.

“Gilead has taken the position that the government’s patents are not valid. We would like to understand whether these patents played any role in negotiations between the company and the Department of Health and Human Services (HHS) and whether Gilead has otherwise engaged in negotiations with the U.S. regarding these patents,” the lawmakers write.

In an emailed statement to CQ Roll Call, Gilead spokeswoman Sonia Choi wrote “Gilead will respond to the committee in a timely manner. The CDC donation is not related to patents.”

The Oversight letter follows a committee hearing in May in which lawmakers grilled O’Day about escalations in the drug’s price and the role of government research in its discovery. O’Day disputed the government’s patents and downplayed the role of public funds in the discovery of Truvada’s use for HIV prevention.

The company estimates it has spent $1.1 billion on research and development related to Truvada.

Advocates with PrEP4All found that the CDC holds patents on the drug. Their finding was first reported by The Washington Post in March.

Critics who are skeptical of the motives driving Gilead’s donation to the government point to the Trump administration’s ties to the pharmaceutical industry: The White House’s domestic policy chief is Joe Grogran, who immediately prior worked as Gilead’s top lobbyist in Washington. U.S. Health and Human Services Secretary Alex Azar was hired from drugmaker Eli Lilly.

“Gilead announced its donation program, which frankly is a drop in the bucket when compared to need for the drug, as members of Congress turned their attention to the government’s central role in development of Truvada for PrEP,” said Gregg Gonsalves, an assistant professor at the Yale Institute for Global Health.

“Did it give cover to an administration and an agency run by a former drug company executive [HHS Secretary Alex Azar] to ignore its own patent rights in this situation?” Gonsalves said. “Hard to ascribe direct motivation to the actors in this drama without proof of an explicit arrangement, but it does offer a weak excuse to Secretary Azar to ignore CDC’s patent rights in the US at the same time it enforces them in other countries.”

The committee is also seeking information about Truvada for PrEP’s price increases, including company analyses of how the price may have shaped the quantity of the drug sold to commercial payers as well as government health programs like Medicare and Medicaid.