A top Republican fundraiser close to President Donald Trump was in negotiations to earn tens of millions of dollars if the U.S. Justice Department dropped its investigation into a multibillion-dollar graft scandal involving a Malaysian state investment fund, according to emails reviewed by The Wall Street Journal.

In emails dated during the past year, Elliott Broidy, a venture capitalist and a longtime Republican donor, and his wife, Robin Rosenzweig, an attorney, discuss setting up a consulting contract with Jho Low, the Malaysian businessman at the center of the 1Malaysia Development Bhd. scandal, which brought scrutiny to the country’s prime minister, Najib Razak. The messages include draft agreements between Ms. Rosenzweig’s California law firm and representatives of Mr. Low about the possible terms of their business engagement. In one draft, there is a proposal that includes a $75 million fee if the Justice Department quickly drops its investigation.

Along with the contract drafts, the emails also appear to show Mr. Broidy prepared talking points for Malaysia’s prime minister ahead of a 2017 visit to Washington that included a meeting with Mr. Trump and other officials. In the talking points, the prime minister was advised to state that Malaysia wanted to emphasize its work with the U.S. in confronting North Korea, while also arguing against the U.S. legal pursuit of the 1MDB matter. It isn’t clear what, if anything, came of the talking points.

The details of the purported effort to influence the Justice Department investigation were included in a cache of emails from Mr. Broidy’s and his wife’s email accounts that were provided to the Journal.

Mr. Broidy was a vice chairman for the Trump campaign’s joint fund with the Republican Party during the 2016 campaign, helping it raise more than $108 million. A longtime Republican donor, he gave more than $160,000 last year to the Republican National Committee, where he is currently a national deputy finance chairman. In March, Mr. Trump is set to attend a fundraiser in Los Angeles that Mr. Broidy helped organize.