Spc. William Colton Millay, 22, was being held without bail at the jail in Anchorage under an agreement between the federal government and the city, the Anchorage Daily News reported. He was arrested Friday morning at Joint Base Elmendorf-Richardson outside Anchorage and transferred to the jail in the evening.
The military has released few details about the case, the News said. The arrest was made by Army counterintelligence officers and the Army Criminal Investigation Command.
Eric Gonzalez, an FBI spokesman in Anchorage, said Millay's arrest followed a joint investigation by his agency and the counterintelligence service.
Bloggers have suggested Millay's arrest was related to the release of documents to WikiLeaks. Gonzalez told the news that was not the case.
Millay was in the rear detachment of the 164th Military Police company, the "Arctic Enforcers." Most of the company was deployed to Afghanistan in March with a small group remaining behind at Elmendorf-Richardson.