Tory leader David Cameron called for a full-scale inquiry to determine if ministers or special advisers were to blame, The London Guardian said Wednesday.
Cameron's demand came after Metropolitan Police's deputy assistant commissioner Peter Clarke spoke out on recent leaks, the newspaper said.
"Perhaps they look to curry favor with certain journalists, or to squeeze out some short-term presentational advantage," Clarke said. "They reveal sources of life-saving intelligence. In the worst cases they put lives at risk."
Blair said that as far as he is aware the leaks did not come from a government minister, civil servant or special adviser.
"But let me make it absolutely clear that I completely condemn any leaks of sensitive information, from whatever quarter," Blair said.