MSBC’s Lawrence O’Donnell admitted he “made an error of judgment” on reporting a single-source, unconfirmed story claiming Pres. Donald Trump had Russian oligarchs as co-signers to his loans.

“This single source close to Deutsche Bank has told me that the Trump — Donald Trump’s loan documents there show that he has co-signers. That’s how he was able to obtain those loans. And that the co-signers are Russian oligarchs,” O’Donnell alleged, according to Mediaite which posted video of his comments.

He added, according to CNN, “I want to stress that is a single source, that has not been confirmed by NBC News. I have not seen any documentation from Deutsche Bank that supports this and verifies this. This is just a single source who has revealed that to me. And that’s where it stands at this point, it’s going to require a lot more verification before that can be a confirmable fact.”

In response, Trump’s attorney Charles Harder demanded a retraction, correction and apology, The Washington Post‘s Paul Farhi reported.

In an Aug. 28 tweet, O’Donnell wrote, “Last night I made an error in judgment by reporting an item about the president’s finances that didn’t go through our rigorous verification and standards process. I shouldn’t have reported it and I was wrong to discuss it on the air. I will address the issue on my show tonight.”

iMediaEthics wrote to MSNBC to ask if it planned to air a correction on air tonight. MSNBC declined to comment to iMediaEthics.