A former commanding officer of the Guantanamo Bay military base in Cuba has been charged with obstruction of justice and accused of lying about a violent confrontation he had with a civilian worker at the base just before that worker was found dead.

The Justice Department announced Wednesday that a Florida grand jury had indicted U.S. Navy Capt. John Nettleton, 53, on charges of obstruction, concealment, falsifying records and false statements during the investigation of the death of Christopher Tur, who worked at the naval exchange.

Tur, 42, was found drowned in the waters of Guantanamo Bay on Jan. 11, 2015. The indictment charges that Tur confronted Nettleton two days earlier at a party at the officers club, where Tur accused Nettleton of having an affair with his wife, according to authorities.

Later that night, according to the indictment, Tur went to Nettleton’s residence, and the two engaged in a physical altercation in which Tur was injured. According to the charges, Nettleton did not report that altercation, falsely claiming that he had last seen Tur at the officer’s club, as officials at the base searched for him. Nettleton also did not initially report the accusation of an affair, officials said.

Investigators later found bloodstains at Nettleton’s home that were a DNA match to Tur, according to the indictment. An autopsy found that some of Tur’s ribs had been broken and that he had a laceration on his head, the indictment said.

Investigators also recovered text messages from Nettleton’s daughter from the night of the fight, in which she told a friend, “what I see is this dude standing there on his phone and my dad is lying on the ground I think and like I’m so confused and terrified,” according to the indictment.

In a follow-up text, she said: “my dad’s really drunk and some other dude is here and they’re like getting into a fight downstairs and I’m hiding.”

A lawyer for Nettleton did not immediately respond to a message seeking comment but had previously said his client had nothing to do with Tur’s death.

The 36-page indictment says that despite Nettleton’s denials, he had in fact been engaged in an extramarital affair with Tur’s wife in 2014 and that after Tur’s death, they agreed not to tell investigators about their relationship.