What is the cause of Bruce Lee's death? Did he died by himself or was he murdered?

The official cause of Lee's death was brain swelling as a reaction to aspirin he had taken for a back injury. But there were rumors that he had been poisoned by either the Chinese mafia or powerful members of the Hong Kong film industry.The most popular story printed in the Hong Kong scandal sheets after Lee's death had it that he had been killed by the American Mafia. Apparently, after The Green Hornet, the Mafia wanted to sign him to a contract to become the first Oriental star in Hollywood. Bruce refused,and that was why he had to go back to Hong Kong.While filming the movie The Crow, he was also shot by a gun that was supposed to contain only blanks but in fact had a live round in its chamber.A recurring aspect of the stories concerning Bruce's death is that he did not die in Betty Ting Pei's apartment, that he was killed elsewhere and his body moved there after his demise.Some say that his wife poisoned him because she had links with the mafia & was paid well.Find more on web.