An admiral linked by navy investigators to counterfeit casino chips denied on Sunday that he played any role in making them.

Investigation records say Rear Admiral Timothy M Giardina’s DNA was found on the underside of an adhesive sticker used to alter one of the phony chips, but previously undisclosed emails indicate that the presence of his DNA is not conclusive evidence that he was involved in the fakery.

Giardina was fired last year as deputy commander of US strategic command, which has responsibility for the nation’s entire nuclear weapons force and is based near Omaha, Nebraska. That decision came at an early stage of a navy criminal investigation into the counterfeit chips.

Giardina acknowledged to the Associated Press that he played the fake chips at a poker table in the Horseshoe Casino in Council Bluffs, Iowa, in June 2013. But he denied any involvement in the counterfeiting or even knowing the chips were fakes at the time he used them. The three chips in question were altered with paint and stickers to make genuine $1 casino chips look like $500 chips.

Giardina declined to discuss details. He said he stands behind a detailed written statement he submitted in April 2014 to Admiral Bill Gortney, who at the time was determining disciplinary action against Giardina. The AP on Sunday obtained a copy of that statement, which has not been publicly released and was not included in records of the Giardina case the AP obtained last week under the Freedom of Information Act.

In the statement, Giardina said he deeply regretted having not immediately surrendered to security officers the four chips which he said he found in a toilet stall at the Horseshoe. He said it was an “error of judgment” that he put three of the chips in play at a poker table, and said he was sorry that he subsequently lied in saying he had purchased them from a man in the bathroom.

“I should have either told the truth or remained silent instead of lying about the events when questioned” by an Iowa state investigator on 18 June 2013, he wrote. That was two days after he played the fake chips and casino officials determined they were counterfeits.

He added: “This lapse in judgment does not make me a thief and a criminal.”

Giardina also wrote that he does not have a gambling problem, and does not consider poker a form of gambling.

“Regardless of anyone’s opinion on the matter, disapproval of the legal manner in which I spent portions of my off-duty time is not adequate grounds to allege criminal misconduct,” Giardina wrote.

Giardina had been at risk of being prosecuted by the navy for counterfeiting the chips, but he was instead given what the military calls non-judicial punishment — in this case a letter of reprimand and the loss of $4,000 in salary. Navy officials have said no court martial was sought because the available DNA evidence against Giardina might not hold up in court.

In his April 2014 statement, Giardina wrote that he suspected the chip counterfeiter left them in the bathroom stall “for a reason,” possibly to observe casino security’s reaction when the finder either turned them in or put them in play.

“I do not believe I was singled out to find them, but believe that I was a patsy for someone who wanted the chips to be found,” he wrote.