BOSTON — A friend of the brothers suspected of bombing the Boston Marathon was accused Friday of obstructing the investigation into the deadly attack by deleting information from his computer and lying to investigators.

The friend, Khairullozhon Matanov, 23, of Quincy, was arrested at his apartment. He later appeared in federal court, but entered no plea and was being held until a detention hearing Wednesday.

In describing Matanov’s relationship with bombing suspects Tamerlan and Dzhokhar Tsarnaev, an indictment unsealed Friday revealed new details about what the brothers did in the hours after they allegedly planted two homemade bombs that killed three people and wounded more than 260. About 40 minutes after the bombs went off, Matanov called Tamerlan Tsarnaev and invited him to dinner, the indictment said, and all three of them dined together at a restaurant that night.

Days later, after the Tsarnaevs’ photos were publicly released, Matanov deleted references from his computer to videos and photos of them, a photo of the MIT police officer who authorities say the Tsarnaevs killed days after the attack and files that contained violent content or calls to violence, the indictment alleges.

Matanov is not charged with participating in the bombings or knowing about them in advance, U.S. Attorney Carmen Ortiz said in a statement, but a spokeswoman declined to comment when asked whether additional charges were possible against him.

His lawyer, Edward Hayden, called the allegations unsubstantiated and said his client looked forward to contesting the charges.

“He had no intent to mislead the FBI, and from what I can see, what he said and did didn’t impede the investigation,” Hayden said.

Matanov and Tamerlan Tsarnaev discussed religion together and hiked up a mountain in New Hampshire in order to praise and emulate the training of the mujahedeen, the indictment said.

After the dinner with the Tsarnaevs the night of the bombing, prosecutors said, Matanov told an unnamed witness that he could support the bombings for a “just reason” — for example, if they were done in the name of Islam.

“In the days following the bombings, Matanov continued to express support for the bombings, although later that week he said that maybe the bombings were wrong,” the indictment said.

Matanov realized the FBI would want to talk with him because he shared their “philosophical justification for violence,” federal prosecutors said.

Hayden said Matanov, originally from Kyrgyzstan, came to the U.S. in 2010 on a student visa, attended college briefly, and was later granted political asylum because of unrest in Kyrgyzstan. He said Matanov, who works as a cab driver, left his parents and brothers behind and had no family in the U.S.

“He’s very frightened — very frightened,” Hayden said, adding that Matanov spoke with investigators several times.

Prosecutors said Matanov asked a friend to destroy his cellphones after the Tsarnaevs were identified as suspects, but that friend refused.

Dzhokhar Tsarnaev, 20, has pleaded not guilty to 30 federal charges and is awaiting trial. Tamerlan Tsarnaev, 26, was killed during a gunbattle with police days after the bombings.