The U.S. Army inspector general is investigating whether aides to former Afghanistan commander Gen. Stanley McChrystal were insubordinate when they made a series of derogatory comments about top civilian leaders to a Rolling Stone reporter, McClatchy Newspapers has learned.

WASHINGTON — The U.S. Army inspector general is investigating whether aides to former Afghanistan commander Gen. Stanley McChrystal were insubordinate when they made a series of derogatory comments about top civilian leaders to a Rolling Stone reporter, McClatchy Newspapers has learned.

The investigation comes as the Pentagon grapples with how much access the reporter who wrote the piece, Michael Hastings, should have to troops. Hastings was banned from a scheduled embed this September in Afghanistan for being untrustworthy, Col. David Lapan, the director of the Pentagon press office, said Tuesday.

Last month, however, the Army granted Hastings an interview with forces he’d embedded with previously in Afghanistan, saying it saw no harm.

The IG investigators have finished questioning officials and are completing the investigation, Army officials told McClatchy. The officials confirmed the investigation but wouldn’t say who asked for it or specify what its scope is. The investigation began shortly after McChrystal was relieved of his command in June.

Maj. Gen. William McCoy Jr. said the investigation “is in review” but declined other comment.

Among those who’ve been interviewed are staff members of Rolling Stone, one Defense Department official told McClatchy. He spoke only on the condition of anonymity because the investigation is ongoing and can’t be discussed publicly. Hastings declined to comment.

The Army inspector general can investigate whether military personnel have violated the Uniform Code of Military Justice, the military standards of conduct or Army regulations.

Article 88 of the Uniform Code of Military Justice says that an officer can face court-martial for speaking ill of his civilian leadership: “Any commissioned officer who uses contemptuous words against the president, the vice president, Congress, the secretary of defense, the secretary of a military department, the secretary of transportation or the governor or legislature of any state, territory, commonwealth or possession in which he is on duty or present shall be punished as a court-martial may direct.”

If the IG finds violations, he must inform whoever asked for the investigation, and the Army will be compelled to respond.

Shortly after the Rolling Stone article was published, McChrystal was summoned to the White House and relieved of command. He then retired from the Army, which took effect Sunday. Several of McChrystal’s aides, who weren’t named in the story, remain in the Army, however.

In the article, “The Runaway General,” one unnamed McChrystal aide ridicules Vice President Joseph Biden — who’d opposed the troop “surge” for Afghanistan — and another describes Richard Holbrooke, the U.S. special envoy for Afghanistan and Pakistan, as a “wounded animal.”

McChrystal is quoted as saying that the U.S. ambassador in Kabul, Karl Eikenberry, who wrote an e-mail opposing sending the additional troops, “covers his flank for the history books.” A McChrystal aide calls national-security adviser Jim Jones, a retired Marine general, a “clown.”

McChrystal has never disputed the accuracy of the account.

The White House didn’t respond Tuesday to e-mails seeking comment.