LONDON (Reuters) - Egypt's new vice president, Omar Suleiman, has long sought to demonise the opposition Muslim Brotherhood in his contacts with sceptical US officials, leaked diplomatic cables show, raising questions whether he can act as an honest broker in the country's political crisis. US Embassy messages from the anti-secrecy WikiLeaks cache of 250,000 State Department documents, which Reuters independently reviewed, also report that the former intelligence chief accused the Brotherhood of spawning armed extremists and warned in 2008 that if Iran ever backed the banned group, Tehran would become "our enemy." The disclosure came as Suleiman met on Sunday with opposition groups, including the officially banned Brotherhood, to explore ways to end Egypt's worst political crisis decades. Suleiman privately voicing disdain for the Brotherhood will not surprise Egyptians, used to the Mubarak government's anti-Islamist stance. The comments could stoke suspicions, though, as he seeks to draw the long-banned movement into a broad dialogue on reform in response to mass protests. The clear implication in the cache of State Department cables was that US officials were sceptical of Suleiman's effort to depict the Brotherhood as "the bogey man." "We decline to comment on any individual classified cable," US State Department spokesman P.J. Crowley said when asked about the documents seen by Reuters. In a cable dated Feb 15, 2006, then-ambassador Francis Ricciardone reported that Suleiman had "asserted that the MB (Muslim Brotherhood) had spawned '11 different extremist organizations,' most notably the Egyptian Islamic Jihad and the Gama'a Islamiya (Islamic Group)." Egyptian security forces crushed groups that targeted tourists, Christians, government ministers and other officials in a 1990s campaign for a purist Islamic state, and has kept a tight lid on them since. The Brotherhood once had a secret paramilitary section, but it now says it is committed to promoting its policies through peaceful, democratic means. The government has been unable to prove any serious act of violence orchestrated by the movement's leadership for more than 50 years. Suleiman, then Mubarak's top spymaster, was speaking to FBI Director Robert Mueller, who was visiting Cairo in February 2006, the 2006 cable says. The cable, which uses the spelling Soliman, said he had told Mueller that the Brotherhood was "neither a religious organization, nor a social organization, nor a political party, but a combination of all three." The cable went on: "The principal danger, in Soliman's view, was the group's exploitation of religion to influence and mobilize the public." "Soliman termed the MB's recent success in the parliamentary elections as 'unfortunate', adding his view that although the group was technically illegal, existing Egyptian laws were insufficient to keep the MB in check." The cable was referring to parliamentary elections in November and December of 2005 in which the Brotherhood made strong gains, although Mubarak's National Democratic Party kept a big majority. In a cable dated Jan. 2, 2008, Ricciardone reported Suleiman as saying that Iran remained "a significant threat to Egypt". In a cable dated Oct. 25, 2007, Ricciardone said Suleiman "takes an especially hard line on Tehran" and frequently refers to the Iranians as "devils." The cables suggest US officials have consistently responded skeptically to the Egyptian government's dire warnings about the Brotherhood. In a Nov. 29, 2005, cable to Mueller before his visit, Ricciardone said Egyptian authorities "have a long history of threatening us with the MB bogeyman." "Your counterparts may try to suggest that (then President George W. Bush's) insistence on greater democracy in Egypt is somehow responsible for the MB's electoral success," he wrote. "You should push back that, on the contrary, the MB's rise signals the need for greater democracy and transparency in government."