BOSTON (Reuters) – A college friend of the Boston Marathon bombing suspect lied to the FBI about visiting the suspect's dorm room house before the accused bomber and his brother engaged in a gun battle with police, a U.S. prosecutors told a court on Monday.

Robel Phillipos, a 21-year-old resident of Cambridge, Massachusetts, is one of three people who prosecutors say went to accused bomber Dzhokhar Tsarnaev's room at the University of Massachusetts at Dartmouth on April 18, 2013, after the FBI released images of the Tsarnaev brothers, and removed a backpack containing empty fireworks shells.

"What did these three men do when they recognized their friend as a suspect in the Boston Marathon bombing investigation? They went to his dorm room," said John Capin, an assistant U.S. attorney, in opening statements at Phillipos' trial.

The other two friends were Kazakh exchange students Azamat Tazhayakov and Dias Kadyrbayev. Tazhayakov was found guilty of obstruction of justice for taking the backpack and tossing it into a dumpster, and Kadyrbayev pleaded guilty to the same charges.

Capin noted that before tossing the bag in a dumpster, Kadyrbayev said to Tazhayakov and Phillipos that they should dispose of it.

"What did the defendant say in response? 'Do what you got to do,'" Capin said. "At about the same time this conversation was going on, there was a shootout in Watertown between the suspects and police."

Phillipos, a U.S. citizen who has been largely confined to his home since his arrest last year, could face up to 16 years in prison if convicted of lying to investigators. The slightly built man appeared at U.S. District Court in Boston dressed in a suit and tie, and did not speak during the early part of proceedings.

Prosecutors contend that he initially denied entering Tsarnaev's dorm room hours after the FBI released photos of Tsarnaev and his older brother Tamerlan Tsarnaev. The authorities were asking for the public's help in identifying the pair who they contend set off the two homemade bombs that killed three people and injured more than 260 near the Boston Marathon finish line on April 15, 2013.

Around the time of the visit to Tsarnaev's dorm room, the brothers were preparing to flee Boston, and they shot dead a university police officer in an unsuccessful attempt to steal his gun, prosecutors say. Later that night, Tamerlan Tsarnaev died after a shootout with police.

Phillipos, Tazhayakov and Kadyrbayev are not charged with playing any role in the bombing.

The surviving Tsarnaev, 21, faces the death penalty if convicted of carrying out the bombing. His trial is set to begin in January.

(Reporting by Scott Malone; Editing by Mohammad Zargham)