USS Boxer off the coast of Kenya.
The U.S. Navy's amphibious assault ship USS Boxer crosses the Likoni Channel in 2009 as it makes its way to the Kenyan port city of Mombasa. REUTERS/Joseph Okanga (KENYA MILITARY)

"It started with pop-ups," a U.S. Navy admiral told investigators who discovered that he had watched porn for hours on multiple occasions on a government computer, a Pentagon report revealed Tuesday. Rear Adm. Richard Williams, who was staying on the USS Boxer on two different occasions when the offenses took place, was removed from his post as commander of the Carrier Strike Group 15 in the first week of 2016 and strongly reprimanded in a punitive letter for watching nine hours of pornography in total.

“I'm guilty; I didn't know it was this much,” said Williams, according to a report made available following a request under the Freedom of Information Act by Stars and Stripes.

During a hearing into the issue, Williams told U.S. Navy investigators that he did not intend to look at porn on the computer and only followed the links after pop-up advertisements prompted him to do so. He is also accused of looking at images of women in bikinis on his government computer at his regular office at the North Island Naval Air Station in San Diego. However, the admiral denied viewing porn on that computer.

Williams first watched porn for four hours during a stay on the amphibious assault ship USS Boxer between Aug. 31 and Sept. 5, in the middle of Operation Dawn Blitz while working alongside the Japanese navy. Then he watched for five hours while also staying on the same ship in December.

The indiscretion came to light during a routine security check of the ship’s computers by Navy Information Operations Command in San Diego, the investigation said.

During an initial hearing in January, a source told the Navy Times that there was enough porn to suggest that Williams “knew it was not just an error.”

Williams started out his U.S. Navy career after graduating from the Rochester Institute of Technology in 1984. It's not yet clear if he will be discharged.