A Somali man who admitted his role in a pirate attack on a U.S.-flagged ship off the coast of Africa was put in extreme isolation after the government claimed he ordered from prison the killing of another ship's captain, his lawyers said Wednesday as they asked a judge to be lenient on him at sentencing this month.

The lawyers disputed the government's account of messages Abdiwali Abdiqadir Muse is accused of sending from his cell at a federal lockup in lower Manhattan to pirates holding the crew of a Taiwanese fishing vessel. They said the government erred in translating his conversations to think he was ordering a hit on the captain, who eventually was freed.

U.S. Attorney Preet Bharara's spokeswoman Jessie Irwin declined to comment Wednesday.

Muse is scheduled to be sentenced Feb. 16. He pleading guilty last year to hostage-taking and conspiracy after he led a band of four pirates who attacked the Maersk Alabama ship on April 8, 2009, as it transported humanitarian supplies about 280 miles off the coast of Somalia. His case was called the first U.S. piracy prosecution in decades.

The ship's captain, Richard Phillips, of Underhill, Vt., was held for several days on an enclosed lifeboat until U.S. Navy sharpshooters killed three pirates in a dramatic nighttime rescue that left him untouched.

Muse's lawyers have asked a judge to sentence him to no more than 27 years in prison, the minimum sentence called for in his plea agreement with prosecutors. The maximum sentence called for in the deal is just under 34 years.

In papers filed Wednesday in U.S. District Court, lawyers for Muse recounted his childhood in the Puntland province of Somalia, saying he suffered from hunger and malnutrition as a child and was living on his own and working odd jobs by age 11 or 12.

The lawyers said he later moved to the coastal fishing village Garacad to learn to be a fisherman but found himself with pirates attacking the Maersk Alabama by the time he was 16.

Muse's age has remained in dispute, and the Bureau of Prisons lists him as 21.

During the attack on the Maersk Alabama, Muse tried to negotiate with the Navy to trade Phillips for the safe release of himself and the other pirates, the lawyers said.

Muse convinced his three companions that they had to release the captain immediately, and they were surrendering when he "heard a stream of gunshots and was thrown to the ground," his lawyers said.

Muse doesn't believe any of the men was holding a gun to the captain when they were killed, the lawyers said, and he "believes that he was betrayed by the Navy, who had come to an agreement with him that his companions would not be harmed."

For a year, Muse has been isolated in prison after the captain of a yacht that was seized by pirates and later was released told the FBI that a Somali pirate told him repeatedly in July or August 2009 that Muse had sent a message from prison instructing the pirates to kill the captain of the Taiwanese fishing vessel, Win Far 161, the lawyers said.

The government said the yacht captain's account was supported by two of Muse's prison call recordings, according to the lawyers. The fishing vessel, hijacked in April 2009, was released in February 2010 with all 28 crew members well.

Special measures were imposed on Muse to severely limit his communications, the lawyers said. He was prevented from communicating with family except for one 15-minute call to his mother every month, his radio privileges were taken away, his reading materials were severely limited, television was ruled out and he was not allowed to exercise outside or attend religious services, the lawyers said. He even had to eat his meals alone in his cell, they wrote.

The lawyers said they strongly disputed the allegation that Muse had threatened the captain from prison, saying the government had misinterpreted the calls, although they acknowledge that he discussed piracy matters over the phone.

They said the strict measures were relaxed on Jan. 15 but he remained in solitary confinement with the only obvious change being that he was given back his radio — with no batteries.