A Marine admitted at his court-martial Wednesday at Kaneohe Bay that he killed a prostitute in his Waikiki hotel room last year and then dumped her naked body near Yokohama Bay.

Master Sgt. Nathaniel Cosby claimed that Ivanice "Ivy" Harris woke him up after 10 hours of drinking on May 16, demanded money, cut him with a knife as he tried to get her out of his room, and that she died after he put her in a chokehold.

"Were you trying to squeeze her neck?" asked defense attorney Lt. Col. Clay A. Plummer.

"I was trying to submit her," answered Cosby, who weighs 180 to 190 pounds and holds a brown belt in a martial art.

Cosby insisted on the witness stand that he was trying to get Harris out of his hotel room when the fight ensued and the pair ended up on the floor. Harris was described as 5 feet 3 inches tall and weighing 125 pounds.

"Did you murder Miss Harris?" Plummer asked.

"No sir, I did not," Cosby said.

But under questioning from government prosecutor Maj. Douglas C. Hatch, Cosby admitted that he had lied to authorities and everyone else about what happened.

Cosby, 39, is charged with unpremeditated murder, murder while engaging in an inherently dangerous act, obstructing justice and attempting to patronize a prostitute.

The Marine faces the possibility of life without parole in connection with the death of Harris, 29, whose body was found May 20 in kiawe brush near Yokohama Bay on the Waianae Coast.

A jury including two majors, a colonel and a Navy commander and two master sergeants, a master gunnery sergeant and a sergeant major will decide Cosby’s fate.

Closing arguments are scheduled for Thursday.

The self-defense claim, which surfaced Monday during the trial at Marine Corps Base Hawaii, may have come as a surprise to the prosecution, which built its opening arguments on a detailed series of security videos, bank statements and cellphone calls trying to show Cosby met up with Harris, took her to his hotel room, killed her and dumped her body.

The Medical Examiner’s Office said the cause of death was injury to the neck and that the manner of death was homicide.

Videotape showed Cosby meeting Harris outside Kelley O’Neil’s pub at about 3:30 a.m. May 16, and holding hands and kissing her in an Aston Waikiki elevator on the last day she was seen alive.

Cosby, an explosive ordnance disposal specialist, arrived on Oahu from Iwakuni, Japan, May 15 for a mission with the Joint POW/MIA Accounting Command to China, but he said he was familiar with the island because he had been stationed here before.

After drinking at Tiki’s Grill & Bar and then Kelley O’Neil’s, Cosby said he "vaguely" remembered walking with Harris to his hotel room.

"I know I was talking to her because I saw the (surveillance) video," he said. "But I couldn’t tell you what we were talking about."

Cosby said he didn’t remember going up in the elevator with Harris — also caught on security videotape — but his recollections appeared clearer about being in the room, where he said he sat down on the bed, she went to the bathroom, and he nodded off.

He was in the room with Harris for about two hours before leaving with her body at about 6 a.m., he said.

Cosby said he was awakened by Harris telling him he needed to pay up.

"I was confused," Cosby said in answer to defense lawyer Plummer’s questions. "I had no idea what she was talking about, sir."

He said he was not exactly sure when he realized she was a prostitute.

The pair started swearing at each other, and Cosby said he was trying to get Harris out the door when she cut him with a "lipstick" knife. He said he "might have been" touching her.

Gashed on the forearm, Cosby said, he tried to get the knife, was behind her and had his arm around her neck, and was cut again near his right eye before the pair ended up on the ground.

"It was chaos. She’s kicking. She’s kicking me and I’m just trying to hold on," the Marine said.

At some point, she stopped moving, Cosby grabbed some towels out of the bathroom for his cuts, went back to her, rolled her over, and realized she was dead, he said, crying.

Cosby then said he "panicked."

"Master sergeant in the Marine Corps. I’ve got a family and I’ve got a dead woman in my room," he said.

He said he removed all her clothes because they were covered in his blood and he put her in a Dakine duffel suitcase and dumped her body on the Waianae Coast.

He said he took the battery out of her cellphone so it couldn’t be tracked and threw away her possessions in a dumpster.

Are you denying that you killed her? Plummer asked.

"No, sir," Cosby answered.

Cosby said that before being assigned a lawyer, he told no one the truth.

"I lied," he said.

Harris was originally from Oregon. She was visiting Hawaii to celebrate her 29th birthday with her boyfriend, who was also her pimp.