FBI disputes mother's claim they tracked elder bombing suspect

WASHINGTON (CNN) -- The FBI has flatly rejected an assertion by the mother of the two suspected Boston bombers that the bureau had been tracking her oldest son and had spoken with him last week after the deadly marathon bombing.

The chief spokesman for the FBI, Mike Kortan, said he continues to stand by an FBI statement issued Friday that said that the only communication the FBI ever had with Tamerlan Tsarnaev was an interview agents conducted with him in 2011 at the urging of a foreign government, since identified as Russia.

Zubeidat Tsarnaev, the mother of the suspected bombers, told reporters the FBI had tracked her oldest son for as long as five years.

The FBI on Sunday referred again to the previous statement that agents did not know the identities of alleged bombers Tamerlan and Dzhokhar Tsarnaev until Friday.

Tamerlan Tsarnaev, 26 was killed in a gunfight with police early Friday. Dzhokhar Tsarnaev, 19, was captured Friday night and is hospitalized in serious condition.