Department of Public Safety spokesman Terrel Harris said Thursday a funeral home retained by Tsarnaev's family picked up the 26-year-old's remains.
Authorities are now closer to being able to make public Tsarnaev's cause of death.
The medical examiner determined Tsarnaev's cause of death on Monday, but officials said it wouldn't be disclosed until his remains were released and a death certificate was filed. It was unclear whether the death certificate had been filed.
Tsarnaev's widow, Katherine Russell, who has been living with her parents in North Kingstown, R.I., learned this week that the medical examiner was ready to release his body and wanted it turned over to his side of the family, her attorney Amato DeLuca said days ago.
Tsarnaev's uncle Ruslan Tsarni, of Maryland, said Tuesday night the family would take the body.
"Of course, family members will take possession of the body," Tsarni said.
After a hearse believed to be carrying Tsarnaev's body departed Boston, television stations reported that their helicopters followed it to the Dyer Lake Funeral Home in North Attleboro. About 20 protesters gathered outside the funeral home. An Associated Press photographer later saw a hearse leaving the home escorted by two police cars.
Dyer-Lake Funeral Director Tim Nye told The Sun-Chronicle newspaper late Thursday that the body was only brought to his funeral home temporarily and was transported to another facility, but he didn't say where.
"He is not at our funeral home and we won't be handling final arrangements," Nye said.
Tsarnaev, who had appeared in surveillance photos wearing a black cap and was identified as Suspect No. 1, died three days after the bombing.
The April 15 bombing, using pressure cookers packed with explosives, nails, ball bearings and metal shards near the marathon's finish line, killed three people and injured more than 260 others. Authorities said Tsarnaev and his younger brother later killed a Massachusetts Institute of Technology campus police officer and carjacked a driver, who later escaped.
Authorities said that during the gunbattle with police, the Tsarnaev brothers, ethnic Chechens from Russia who came to the United States about a decade ago, set off another pressure cooker bomb and tossed grenades before the older brother ran out of ammunition.
Police said they tackled the older brother and began to handcuff him but had to dive out of the way at the last second when the younger brother, 19-year-old Dzhokhar Tsarnaev, drove a stolen car at them. They said the younger brother ran over his brother's body as he drove away from the scene to escape.
Dzhokhar Tsarnaev was captured later, wounded and bloody, hiding in a tarp-covered boat in a suburban Boston backyard. He is in a federal prison and faces a charge of using a weapon of mass destruction to kill.
The Tsarnaev brothers' mother insists the allegations against them are lies.
Three of Dzhokhar Tsarnaev's friends, college classmates, were arrested Wednesday and accused of helping after the marathon bombing to remove a laptop and backpack from his dormitory room before the FBI searched it.
A top Republican senator on Thursday asked President Barack Obama's administration to explain how one of the students entered the United States without a valid student visa.
Sen. Chuck Grassley, of Iowa, in a three-page letter to Department of Homeland Security Secretary Janet Napolitano, asked for additional details about the student visa applications for Azamat Tazhayakov and Dias Kadyrbayev, college roommates from Kazakhstan charged with obstruction of justice in the marathon bombing case, and how Tazhayakov was allowed to re-enter the United States in January.
Tazhayakov was a student at the University of Massachusetts Dartmouth when he left the U.S. in December. In early January, his student visa status was terminated because he was academically dismissed by the university.
Peter Boogaard, a DHS spokesman, said Wednesday that when Tazhayakov arrived in January Customs and Border Protection had not been alerted that he was no longer a student. Boogaard said the department was working on a fix to the student visa system.
The third student arrested, Robel Phillipos, was charged with willfully making materially false statements to federal law enforcement officials during a terrorism investigation.
All three men charged in connection with the case began attending UMass Dartmouth with Tsarnaev in 2011, according to the FBI.
If convicted, Kadyrbayev and Tazhayakov could get up to five years in prison and a $250,000 fine. Phillipos faces a maximum of eight years behind bars and a $250,000 fine.
The lawyers for the Kazakh students said their clients had nothing to do with the bombing and were just as shocked by it as everyone else. Phillipos' attorney said the only allegation against him was "he made a misrepresentation."
In other developments:
- Police and politicians across the U.S. are pointing to the example of surveillance video that was used to help identify the Boston Marathon bombing suspects as a reason to get more electronic eyes on their streets. They want to gain police access to cameras used to monitor traffic, expand surveillance networks in some major cities and enable officers to get regular access to security footage at businesses.
- At an interfaith service Thursday night, a member of the executive board of the mosque where the bombing suspects prayed condemned the attacks. Anwar Kazmi said the bombings were a "grotesque perversion of the teaching of our faith."
Associated Press writers Alicia A. Caldwell in Washington, Tami Abdollah in Los Angeles and Rodrique Ngowi in Boston contributed to this report.