IOWA CITY, Iowa (AP) — A congressman from Iowa said in a sworn statement made public Thursday that a company he failed to disclose wasn't "doing business" in 2016, despite claims in its own advertising to the contrary.

GOP Rep. Rod Blum filed an amended personal financial disclosure listing himself as the majority shareholder and director of Tin Moon Corp. He also listed the digital marketing company as an asset, saying it was valued at $700 as of Dec. 31, 2016.

The move came after The Associated Press reported Wednesday that Blum violated House ethics rules by failing to list his ties to Tin Moon in his disclosure covering calendar year 2016, which he submitted last August. Among other services, Tin Moon has promised to help companies cited for safety violations hide their Food and Drug Administration warning letters below positive search results.

Blum says in the amendment dated Wednesday that his failure to disclose was an administrative oversight because Tin Moon was "basically worth less than $1,000 and not doing business in 2016." He certified that his statements were "true, complete and correct."

Anyone who "knowingly and willfully" makes a false statement in the disclosure can face $50,000 in civil penalties or up to five years in prison, although prosecutions are rare and usually tied to broader corruption scandals.

Records show Tin Moon was incorporated and registered its website in early May 2016. In August 2016, YouTube user "rodblum" uploaded an ad urging viewers to "contact Tin Moon today!" The ad featured a woman claiming that Tin Moon had helped her small business improve its online marketing while saving thousands of dollars. Blum congressional aide John Ferland appeared in a similar testimonial that was uploaded two weeks later, falsely posing as a representative of Digital Canal, a construction software company that Blum also owns. It is based in the same Dubuque office as Tin Moon, an address that Blum's re-election campaign also uses.

While Blum claims his 70 percent ownership interest in the company was essentially worthless in 2016, Tin Moon now claims to have "11,000 satisfied clients."

"How much has he really profited from this company? $700 doesn't stack up with 11,000 customers," the Democratic Congressional Campaign Committee, which is working to unseat Blum in November's election, asked in a series of questions for Blum on Thursday.

A phone call to Tin Moon was answered by Monty Alexander, a GOP activist and prominent Blum supporter who has been paid by Blum's campaign for past get-out-the-vote efforts. Alexander is listed as Tin Moon's "reputation management specialist" on a site that promises companies cited for safety violations that it "WILL remove the derogatory FDA letter from page one so it no longer damages your business and reputation."

Alexander, who spent part of Wednesday night sparring with Blum's critics on Facebook, hung up without commenting. Ed Graham, the president of Digital Canal and Tin Moon and the treasurer of Blum's re-election campaign, has not returned messages.

Tin Moon has removed Ferland's false testimonial and an official congressional photo of Blum from its website and changed Blum's title from CEO to "majority shareholder" since the AP began asking questions about Tin Moon this week.