The results from a post-mortem examination on Top Gun film-maker Tony Scott may not be known for six weeks, according to the Los Angeles Department of Coroner.
A spokesman said "further tests" were being carried out after the 68-year-old, originally from North Shields, jumped to his death from a bridge in Los Angeles.
Stars including Tom Cruise, who worked with Scott on Top Gun and Days Of Thunder, praised the man behind a string of action-packed Hollywood blockbusters.
Scott, younger brother of film-maker Ridley Scott, leapt from the Vincent Thomas Bridge in LA and his death is being treated as suicide.
Denzel Washington, frequently the leading man in his films including Crimson Tide and The Taking Of Pelham 123, said: "Tony Scott was a great director, a genuine friend and it is unfathomable to think that he is now gone. He had a tremendous passion for life and for the art of film-making and was able to share this passion with all of us through his cinematic brilliance."
Cruise, who became a major name after being cast in the lead for Top Gun, said he "will really miss him", adding: "He was a creative visionary whose mark on film is immeasurable. My deepest sorrow and thoughts are with his family at this time."
A dive team pulled Scott's body from the water several hours after members of the public alerted emergency services, having seen him jump from the bridge. A suicide note is said to have been found at his office and he had left contact details in his black Toyota Prius parked close to the scene.
The coroner's spokesman denied reports Scott had been diagnosed with brain cancer. He said: "I spoke with Mrs Scott yesterday and she said that was totally false."
Scott, who lived in Beverly Hills, was married to actress Donna Scott, his third wife with whom he had twin sons. He ran Scott Free Productions with his brother and the pair were working on a film called Killing Lincoln.
His other films included box-office hits such as True Romance, Crimson Tide, Enemy Of The State and Man On Fire.