WASHINGTON — Congressional investigators reviewing the failed gun-tracking program Operation Fast and Furious have formally asked the Obama administration to turn over copies of “all records” involving three key White House national security officials and the program, other ATF gun cases in Phoenix, and all communications between the White House and the ATF field office in Arizona.

The letter signed Friday by Rep. Darrell Issa, R-Calif., chairman of the House Committee on Oversight and Government Reform, and Sen. Charles Grassley of Iowa, the top Republican on the Senate Judiciary Committee, was sent to national security adviser Thomas Donilon, a top aide to President Barack Obama.

It marks a significant step in the committee’s investigation into the failed gun-tracking operation, as the committee begins to broaden its investigation from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives and targets White House and Department of Justice officials.

— From wire reports