Looks like the FBI tried to circumvent Jack Anderson's son Kevin (the official custodian of the papers) by trying to get Jack Anderson's elderly widow to release the papers...
http://www.washingtonpost.com/wp-dyn/content/article/2006/04/18/AR2006041800961.htmlAgents Seek Data on AIPAC Case and Classified Papers
The family of the late newspaper columnist Jack Anderson yesterday rejected a request by the FBI to turn over 50 years of files to agents who want to look for evidence in the prosecution of two pro-Israel lobbyists, as well as any classified documents Anderson had collected.
Kevin P. Anderson, son of the storied Washington-based writer, said the family is outraged at what it calls government overreaching and "a dangerous departure" from First Amendment press protections, a stance joined by academic and legal experts.
~snip
Kevin Anderson said FBI agents contacted the columnist's 78-year-old widow about a month after his death seeking access to his reporting materials. Agents subsequently contacted Mark Feldstein, an Anderson biographer who once worked for him and is now a George Washington University professor. Feldstein is helping to arrange the transfer of 188 cartons of material owned by the family from Brigham Young University to GWU.
~snip
Kevin Anderson said agents were "duplicitous" about their "true objective . . . to whitewash Jack Anderson's papers and attempt to remove from history embarrassing documents."
Someone's REALLY eager to get at those papers.