WASHINGTON — The admiral fired last year as No. 2 commander of U.S. nuclear forces may have made his own counterfeit $500 poker chips with paint and stickers to feed a gambling habit that eventually saw him banned from an entire network of casinos, according to a criminal investigative report obtained by The Associated Press.

Although Rear Adm. Timothy M. Giardina’s removal as deputy head of U.S. Strategic Command was announced earlier this year, evidence of his possible role in manufacturing the counterfeit chips has not previously been revealed. Investigators said they found his DNA on the underside of an adhesive sticker used to alter genuine $1 poker chips to make them look like $500 chips.

Nor had the Navy disclosed how extensively he gambled.

The case is among numerous embarrassing setbacks for the nuclear force. Disciplinary problems, security flaws, weak morale and leadership lapses documented by The Associated Press over the past two years prompted Defense Secretary Chuck Hagel on Nov. 14 to announce top-to-bottom changes in how the nuclear force is managed that will cost up to $10 billion.

The records obtained by the AP under the Freedom of Information Act show Giardina was a habitual poker player, spending a total of 1,096 hours – or an average of 15 hours per week – at the tables at the Horseshoe casino in Council Bluffs, Iowa, in the 18 months before being caught using three phony chips in June 2013.

He was such a familiar figure at the casino, across the Missouri River from his office near Omaha, Nebraska, that some there knew him as “Navy Tim.” But they may not have known he was a three-star admiral and second-in-charge at Strategic Command, the military’s nuclear war-fighting headquarters. Strategic Command also plays key roles in missile defense, cyberdefense, space operations and other functions.

A career submarine officer, Giardina is a 1979 graduate of the U.S. Naval Academy.

Such was Giardina’s affection for poker that even after he was caught he “continued to come in and gamble on a regular basis” at Harrah’s casino, also located in Council Bluffs, according to an account by an Iowa Division of Criminal Investigation agent that was turned over to the Naval Criminal Investigative Service after NCIS took over the case in August 2013.

On July 18 Giardina was banned from both the Horseshoe and Harrah’s for 90 days, but he returned at least twice to play poker at the Horseshoe before the ban expired. The second time, in October, he was given a lifetime ban from all gambling establishments run by the Horseshoe’s owner, Caesar’s Entertainment Corp.

At Strategic Command, Giardina was privy to highly sensitive national security secrets.