ABC News reports that a source close to the 68-year-oldTop Gun director informed them of the malady.
Contrary to this report, Deadline claims "informed insiders" close to filmmaker's widow deny he suffered from brain cancer.
The AP reports that following Scott's death, several notes to loved ones were found in his car, which was parked on the Vincent Thomas Bridge in Long Beach, CA, and a suicide note was later found at his office.
Scott's spokesman, Simon Halls, said in a statement earlier today, "I can confirm that Tony Scott has passed away. The family asks that their privacy is respected at this time."
The younger brother of director Ridley Scott, Tony Scott's credits include a range of top Hollywood blockbusters including Days of Thunder, Beverly Hills Cop II, Crimson Tide, Enemy of the State, Man on Fire and Unstoppable.