Democratic Georgia Senate candidate John Ossoff's company was paid thousands of dollars for documentaries that it licensed to Qatar-owned Al Jazeera, Fox News reported, citing the candidate's financial disclosure forms.
Al Jazeera has been criticised for giving a platform to extremists and militants, and publishing content harmful to Arab states.
US State Department internal communications released by WikiLeaks in 2010 included a memo that said the Qatari government manipulates Al Jazeera coverage to suit its political interests.
The station has frequently aired the views of the Doha-based spiritual leader of the Muslim Brotherhood, Yusuf Al Qaradawi. The 93-year-old was banned from France and Britain for his extremist views and has made derogatory references to Jews when speaking about historic fatwas.
Al Jazeera also gave the first media interview to Mohammed Al Joulani, leader of former Al Qaeda affiliate Jabhat Al Nusra, now rebranded as Hayat Tahrir Al Sham.
Mr Ossoff disclosed the Al Jazeera payment in a July update to his forms that included income for Insight TWI, the company that he is the managing director and CEO of. Insight TWI on the form is listed as a "broadcast media production" company, Fox said. Transactions reported on the form were all over $5,000.
Insight TWI produces investigative journalism, often in the form of documentaries, which are then licensed out to other companies that broadcast the content.
Some of the documentaries aired by Al Jazeera, were titled "Latin America Investigates" and "Living with Ebola."
"TV stations and distributors based in 33 countries have licensed and aired Jon’s work, which has exposed corrupt officials, organised crime, and war criminals," Mr Ossoff's spokeswoman Miryan Lipper said.
Mr Ossoff is facing incumbent Republican Senator David Purdue in a January 5 runoff election that will help determine whether Democrats or Republicans win control of the Senate. It is one of two Senate critical run-offs in Georgia. Republican Senator Kelly Loeffler, who took office in January after being appointed by Georgia’s governor, faces Democrat Raphael Warnock in the other race.
The Perdue campaign said the payment from Al Jazeera shows "abysmal judgment", Fox reported.
A win by either Mr Perdue or Ms Loeffler would maintain the Senate majority for Republicans. Dual Democratic victories would yield a 50-50 split in the Senate, with Kamala Harris wielding the tiebreaking vote as vice president.
In September, the US Justice Department ordered online news channel Al Jazeera Plus to register as a foreign agent under the country's lobbying laws.
The Justice Department acted after a finding that AJ+ engaged in political activities in the US, as defined by the Foreign Agents Registration Act.
It said the channel acted at the direction and control of the Qatari leadership.