A Lorton Reformatory inmate, who was severely burned in a methane gas explosion at the prison in December, has been released on parole as a result of executive clemency granted by President Reagan, according to D.C. parole and other officials.

In an order last week, the president commuted a sentence imposed on Arthur Moody, who suffered second- and third-degree burns over 36 percent of his body. Moody, 27, who had been held under guard at D.C. General Hospital, was released Friday and is living at his sister's home, officials said.

Moody, a former part-time employe of a used-furniture store, had been serving a sentence of nine months to two years and three months for unauthorized use of a car and receiving stolen property. He would have become eligible for parole in August, officials said.

In the clemency order, Reagan cited Moody's injuries and said that the "ends of justice require that the present parole eligibility date . . . should be advanced."

"Justice has been done," said the Rev. Eugene Brake, a Catholic priest and volunteer chaplain at Lorton, who had urged clemency for Moody.

"He developed powerfully while in the hospital. He's got his freedom, and he is responding very well," Brake said. "He found the strength he had within himself."

"He's pleased to be out," said Amram Feldman, Moody's lawyer. "He's still in a lot of pain from his injuries." Feldman said Moody would be unavailable for comment because of a lawsuit pending against the city.

In April, Moody sued the District for $15 million in D.C. Superior Court, charging that the Lorton facility had been negligently operated.

Joe Murray, a D.C. parole officer, said Moody must wear a body stocking because of extensive skin grafts stemming from the burns. Moody is under consideration for an alcohol treatment program, officials said, and will remain on parole for nearly two years.

Moody was one of two inmates burned in explosions at Lorton in December. The other inmate, Anthony Johnson, 25, was severely burned Dec. 6 and died Christmas Day.