(ABC NEWS) -- Intelligence community watchdogs are extending their review of what the U.S. government knew beforehand about two brothers accused of carrying out the deadly April 15 Boston Marathon bombings, according to a government letter obtained by ABC News.
The joint letter from four inspectors general addressed to congressional committees that oversee national security, dated Friday, said their final report on what intel agencies knew about Tamerlan and Dzhokhar Tsarnaev before they allegedly used two bombs to kill three people and injure more than 260 others won't be finished this month, as anticipated.
"Information relevant to the review is still being provided to the review teams," the letter reads.
The coordinated review inside the Obama administration is being led by I. Charles McCullough III, the Intelligence Community Inspector General, working with the IGs from the CIA, Department of Homeland Security and Department of Justice.
"The inspectors general have been working diligently toward completing this review," reads the letter from the Intelligence Community Inspectors General Forum. But no completion date was offered. "When all requested information has been received and analyzed, we will be able to provide a better estimate of the timeframe for producing a draft report."
The Office of the Director of National Intelligence declined to say if the review team has faced any resistance from agencies over access to files, witnesses or other information, but one U.S. official insisted to ABC News that there "hasn't been any intransigence" or stonewalling. Read more via ABC News...