The Federal Bureau of Investigation has opened a probe into whether employees of News Corp. might have hacked or attempted to hack into the private calls and phone records of Sept. 11 victims and their families, according to people familiar with the matter.

The investigation was opened Thursday morning, following a request a day earlier by Rep. Peter King (R., N.Y.), who heads the House Homeland Security Committee and whose Long Island district was home to many victims of the 2001 terrorist attacks.

The...