Retired Marine General James Mattis, nominated to be the next secretary of defence, has received millions of dollars of income since leaving the military, including through lucrative speaking engagements with companies such as Goldman Sachs and Northrop Grumman.
He also had paid positions with Theranos, Stanford University and General Dynamics.
The details were disclosed in part through records newly released by the Office of Government Ethics.
Mattis, who retired as chief of US Central Command (Centcom) in 2013, said in a memo to the Pentagon dated January 5 that he will not participate "personally and substantially" in any matters in which he knows he has a financial interest without seeking a legal waiver.
The financial documents were first reported on by Politico.
The general's financial moves since retirement are not uncommon among his peers, who often make far more after leaving the military than they did while serving.
But the newly released documents provide a window into the financial opportunities for a retired senior military leader and present a complication as he is considered by the Senate to be the Pentagon's senior civilian leader.
Mattis's most significant forms of income since retiring include salary of US$419,359 as a distinguished visiting fellow at Stanford's Hoover Institution and fees of US$242,000 as a member of the board of directors at the defence contractor General Dynamics, according to the documents.
Mattis also received US$150,000 in fees as a member of the board of directors at Theranos, the controversial Silicon Valley blood-testing firm. He pushed for its technology to be incorporated while chief of Centcom, according to emails obtained and previously detailed by the Washington Post. The usefulness of the firm's technology was called into question, and it has since fallen from grace and laid off dozens of employees.
As a retired four-star officer with 41 years of service ending in 2013, he also is entitled to an annual federal pension of more than US$240,000.
Mattis's positions with Stanford, General Dynamics and Theranos all have been previously reported. He already has resigned from the Theranos board and other leadership positions, including at the Centre for a New American Security, the Marines' Memorial Club in San Francisco, the Marine Corps Scholarship Foundation and the Tri-Cities Food Bank in his home state of Washington. He will resign from Hoover and General Dynamics if confirmed, his memo said.
The honorariums that Mattis received include several US$25,000 appearances, including one each with Lincoln Financial Services, Citi Corp., and the World Presidents Organisation, a group of chief executives. Mattis also received US$20,000 each for appearances with Goldman Sachs, Northrop Grumman, DirecTV and the Howard Buffet Foundation.
Other honorariums include US$16,000 for speaking to the Global Leadership Coalition, US$15,000 for speaking at the July 2015 conference for the Veterans of Foreign Wars, and US$12,500 for speaking to the American Society for Industrial Security International. Mattis received several other honorariums of a few thousand dollars each.