Michael Flynn, who was compelled to resign as national security adviser last month amid a controversy over his alleged contacts with Russia's ambassador to the United States, is in the news again for another Russia-related incident. He collected almost $68,000 in fees from Russian government-backed television network RT during a trip to Moscow in December 2015, according to newly released documents.

Released by Elijah E. Cummings, a top Democrat on the House Oversight and Government Reform Committee, the documents show the amount is higher than what was previously known. They show that $45,386 was paid by the RT network to Flynn, $11,250 by the U.S. subsidiary of a Russian cybersecurity firm, Kaspersky Lab, and another $11,250 by Volga-Dnepr Group, a Russian airline that has a U.S. air cargo affiliated with it.

Read: Russian Ambassador, Flynn Wiretapped, Moscow Diplomat Claims

Flynn had reportedly said earlier he did not charge any money for his 2015 Moscow trip.

Cummings questioned President Donald Trump, Defense Secretary Jim Mattis and FBI Director James B. Comey whether Flynn's fees violated prohibitions on retired military officers accepting payments or gifts from foreign governments.

"The Emoluments Clause of the Constitution prohibits any person 'holding any Office of Profit or Trust' from accepting gifts or payments from any foreign government or agent without the consent of Congress. The Department of Defense has made clear that this Constitutional provision applies to retired military officers, such as Lieutenant General Flynn, because they continue to hold offices of trust. It also applies to 'indirect' sources of payment, including payments made through intermediaries in the United States," the document read.

Meanwhile, Russian news network RT has responded to disclosure of Flynn's payments.

"The U.S. media is 'losing its mind' over a totally common and transparent practice," RT’s head of communications Anna Belkina said. She added that Flynn’s paid appearance at a conference in Moscow was never a secret.

“This isn’t just a standard practice, this is a standard practice that is entirely transparent. It’s commonplace not just in the United States, but in Washington, D.C., in particular,” Belkina said. She also said there are many agencies in the U.S. that connect public figures with events such as the international conference hosted by RT in Moscow in December 2015, that Flynn attended.