Sri Lankan defence secretary Gotabhaya Rajapaksa has hinted that Tamil Tigers chief Velupillai Prabhakaran might have been killed in the air raid on his bunker on Nov 26. "Our intelligence sources believe that he (Prabhakaran) was seriously injured or killed. It is obvious that the LTTE will not divulge this for a long period," Rajapaksa told government-run ‘Sunday Observer’. He discounted the validity of the pictures put out by the LTTE of Prabhakaran delivering his annual Heroes’ Day address over TV and radio on November 27, a day after he was supposedly injured or killed in an air raid. "The LTTE can also publish pictures but (the pictures) do not give any indication that he is alive, until he comes for a public meeting," Rajapaksa said.