Jihad tape of mother and Boston bomber not passed on to US Anzor and Zubeidat Tsarnaeva, parents of the suspected Boston bombers, at a news conference. Russian authorities secretly recorded a telephone conversation in 2011 in which one of the Boston bombing suspects vaguely discussed jihad with his mother, officials say. In another conversation, the mother of now-dead bombing suspect Tamerlan Tsarnaev was recorded talking to someone in southern Russia who is under FBI investigation in an unrelated case. Had the conversations been revealed earlier, they might have been enough evidence for the FBI to initiate a more thorough investigation of the Tsarnaev family. Russian authorities told the FBI only that they had concerns that Tamerlan and his mother were religious extremists. With no additional information, the FBI conducted a limited inquiry and closed the case in June 2011. Two years later, authorities say Tamerlan and his brother, Dzhohkar, detonated two homemade bombs near the finish line of the Boston Marathon, killing three and injuring more than 260. Tamerlan was killed in a police shoot-out and Dzhohkar is under arrest. In the past week, Russian authorities turned over to the US information on 26-year-old Tamerlan and his mother, Zubeidat Tsarnaeva, ethnic Chechens who emigrated from southern Russia to the US in the past 11 years. In early 2011, the Russian FSB internal security service intercepted a conversation between Tamerlan and his mother vaguely discussing jihad, according to US officials who spoke on condition of anonymity. The two discussed the possibility of Tamerlan going to Palestine but he told his mother he didn't speak the language there, according to the officials. In a second call, Zubeidat Tsarnaeva - who has denied terrorist links - spoke with a man in the Caucasus region of Russia who was under FBI investigation. Nothing in the conversation suggested a plot inside the US, officials said. It is not clear why Russian authorities did not share more information at the time.