- Khairullozhon Matanov is charged with destroying evidence in Boston blasts
- He also faces three counts of making false statements to investigators
- Defense lawyer Edward Hayden says indictment was based on "unsubstantiated allegations"
- He is not charged with the bombings, but with trying to hide ties to the Tsarnaev brothers
A Massachusetts man pleaded not guilty Wednesday to obstructing the investigation of the 2013 Boston Marathon bombings, federal prosecutors said.
Khairullozhon Matanov, 23, of Quincy was charged with "one count of destroying, altering, and falsifying records, documents, and tangible objects in a federal investigation, specifically information on his computer, and three counts of making materially false, fictitious, and fraudulent statements in a federal terrorism investigation," according to the U.S. attorney's office for Massachusetts.
Matanov pleaded not guilty to all four counts, his lawyer Edward Hayden told CNN.
Hayden maintains that the indictment was based on "unsubstantiated allegations."
Matanov agreed to voluntary detention Wednesday because he doesn't have a home and his family is out of the country, Hayden said. A hearing was set for July 15, according to the U.S. attorney's office.
Authorities say brothers Dzhokhar and Tamerlan Tsarnaev planted bombs at the finish line of the 2013 race.
Tamerlan Tsarnaev was killed during a subsequent manhunt that paralyzed Boston. Dzhokhar Tsarnaev has pleaded not guilty to killing four people -- including three killed by the bombings -- and wounding more than 200 others.
Matanov is not charged with participating in the bombings, and prosecutors said that Matanov did not know about the bombings beforehand.
But about 40 minutes after the blasts, Matanov bought dinner for the brothers, according to the indictment. In the hours and days after the bombings, Matanov contacted and attempted to contact the suspects by phone and saw Tamerlan Tsarnaev at least twice, according to the indictment.
Matanov allegedly tried to give away his cell phone to friends and deleted hundreds of videos and documents from his computer. Authorities allege he misled police about the extent to which he knew the brothers.
He also hid that he shared the "philosophical justification for violence" that the Tsarnaev brothers held, the U.S. attorney's office said last week.
If convicted, Matanov faces up to 20 years in prison for the destruction of evidence charge, and eight years for each of the false statement counts.