04/17/2013 at 02:20 PM EDT
Federal officials are denying that a suspect is in custody in the Boston Marathon bombings.
A law enforcement official briefed on the investigation told The Associated Press on Wednesday a suspect was in custody.
But the FBI and the U.S. attorney's office in Boston dispute that.
The conflicting information comes after several media outlets reported that one, and possibly two suspects had been identified from surveillance video taken at a Lord & Taylor store between the sites of the two bomb blasts, which killed three people and wounded more than 170.
The official was not authorized to divulge details of the investigation and spoke to The Associated Press on condition of anonymity. The suspect was expected at a Boston courthouse, the official said.
A news briefing was scheduled later Wednesday.
Law enforcement agencies had earlier pleaded for the public to come forward with photos, videos or any information that might help them solve the twin bombings.
Investigators circulated information about the bombs, which involved kitchen pressure cookers packed with explosives, nails and other lethal shrapnel. But the FBI said nobody had claimed responsibility.
A person close to the investigation had previously told AP the bombs consisted of explosives put in 1.6-gallon pressure cookers, one with shards of metal and ball bearings, the other with nails.
Investigators in white jumpsuits had fanned out across the streets, rooftops and awnings around the blast site in search of clues on Wednesday. They combed through debris amid the toppled orange sports drink dispensers, trash cans and sleeves of plastic cups strewn across the street at the marathon's finish line.
President Barack Obama branded the attack
an act of terrorism. Obama plans to attend an interfaith service Thursday in the victims' honor in Boston.