SoftBank contributed $50 million to the Trump Presidential Library in January, just months before announcing that it’s leasing land from the federal government to build a sprawling data center in Ohio. The Japanese company revealed the timing in response to a June letter from Sen. Elizabeth Warren (D-MA), Sen. Richard Blumenthal (D-CT), and Rep. Melanie Stansbury (D-NM), which raised concerns about bribery.

“Are we expected to believe it’s a coincidence that two months after Softbank donated $50 million to the Trump library, his administration announced a massive lease deal for Softbank’s data center?” Sen. Warren said in a statement to The Verge. “Again and again, it seems like Trump is putting handshake deals with CEOs over what’s best for Americans.”

In March, SoftBank said its SB Energy subsidiary formed a public-private partnership to build “the world’s largest” AI data center at the US Department of Energy’s site in Portsmouth, Ohio. As part of the partnership, SB Energy will build a massive gas-fired powerplant nearby, with a capacity of at least 9.2 gigawatts.

As the lawmakers note in their initial letter, SoftBank has made contributions to the presidential libraries of Ronald Reagan and George W. Bush, but only “after those presidents had left office and after the relevant library foundations and institutions had been established.” With Trump’s presidential library, however, SoftBank donated during Trump’s term and “before any presidential library has been constructed.”

Additionally, the organization responsible for taking donations, the Donald J. Trump Presidential Library Fund, had been dissolved by the state of Florida last September after failing to file an annual report. SoftBank says in its response that it made its $50 million contribution to the Donald J. Trump Presidential Library Foundation, Inc.

Donald Trump’s son, Eric Trump, is a trustee of the nonprofit, Citizens for Ethics reports. “As with its prior contributions to Presidential libraries, SoftBank understands that this donation will be used to support the construction and operation of the Donald J. Trump Presidential Library,” SoftBank’s letter reads.