Army Maj. Gen. Wayne W. Grigsby Jr. makes opening remarks at a conference in Nairobi in April 2015. Grigsby has since been demoted by the Army and forced to retire after an investigation determined that he had an inappropriate relationship with a junior officer. (Staff Sgt. Carlin Leslie/U.S. Air Force)

The Army has demoted the former commander of the 1st Infantry Division for having “an inappropriate relationship” with a junior officer, the latest in a string of episodes in which Army generals have landed in trouble for personal misconduct.

Wayne W. Grigsby Jr., who also served as the commander of Fort Riley, Kan., was reprimanded and demoted from major general to brigadier general after investigators found that he had called and texted a female captain more than 850 times over 10 months and was spending time at her home, according to Army documents obtained by The Washington Post.

Grigsby is the sixth general in the past year whom the Army has punished for sexual misconduct or improper interactions with women. Although Army leaders have been reluctant to talk publicly about the issue, the service in December appointed a three-star general to lead a review of its general-officer corps.

The Army abruptly relieved Grigsby of command last September, citing a “loss of confidence” in his ability to lead. But officials provided no other details and kept the outcome of the investigation a secret for six months.

Grigsby received a formal reprimand from the Army in April. He is scheduled to retire Aug. 1. Although he and the unidentified female captain both declined to talk to investigators, Grigsby submitted a letter to the Army accepting responsibility for “my inappropriate behavior.”

Army Maj. Gen. Wayne W. Grigsby Jr., then commanding general of the Combined Joint Task Force - Horn of Africa, visits U.S. Marines in d'Arta Plage, Djibouti, in November 2014. (Cpl. Jonathan Waldman/U.S. Marine Corps)

In a statement to The Post, Grigsby said he was “embarrassed and disappointed in myself” but did not elaborate on his conduct. He apologized for causing “pain” to his family and the Army.

Documents show that the Army and Pentagon inspectors general received a flurry of complaints last year from soldiers at Fort Riley who suspected that Grigsby was having an affair and that it was affecting his ability to lead.

One anonymous complainant noted that Grigsby’s wife was aware of his relationship with the female captain, had moved out of their quarters at Fort Riley and had “posted messages regarding cheating on Twitter,” according to a report by the Army inspector general that was completed in December.

Grigsby’s chief of staff and command sergeant major confronted him and “told him flat out that there was a very serious perception out there; ‘people are talking about it, you need to stop,’ ” according to the report.

Others told investigators that the relationship distracted Grigsby from his unit’s upcoming deployment to Iraq. One soldier said it “was affecting careers. He did not want it to get to the point where it was affecting lives,” the report stated.

Other branches of the armed forces have had similar problems. The Navy is grappling with an epic sex-for-secrets scandal involving 30 admirals linked to an Asian defense contractor.

In February, the Air Force took the unusual step of disciplining a retired four-star general for engaging in “inappropriate sexual acts” with a subordinate female officer while he was on active duty.

The Army typically discloses details of investigations of senior officers only in response to Freedom of Information Act requests, which officials often take several months to process.

In April, the Army’s Military District of Washington announced that it had filed criminal charges against a retired major general, James Grazioplene, for alleged child rape in the 1980s. But officials have withheld charging documents that are ordinarily part of the public record.

Grazioplene, of Gainesville, Va., retired in 2005. He did not respond to emails seeking comment. If the case goes to trial, it would be only the fourth time in more than 60 years that an Army general has faced court-martial.

In another case, documents obtained by The Post show that the Army reprimanded the commander of the 46th Military Police Command last year for having an affair.

Brig. Gen. Michael T. White, who led the command as part of the Michigan Army National Guard, had a two-year-long sexual relationship with a married woman, according to a reprimand he received in August.

Adultery is illegal under military law. White did not respond to requests for comment.

In September, USA Today reported that Brig. Gen. Michael Bobeck, an officer on the Joint Staff at the Pentagon, had been fired for having an affair.

USA Today also reported in July that the Army had secretly relieved a two-star general for carrying on a “swinger lifestyle” for a decade. Officials feared the general, David Haight, was at risk of being blackmailed.