Republican presidential hopeful Herman Cain has strongly denied allegations of sexual harassment against him dating from the 1990s. "Never have I committed any sort of sexual harassment," he told Fox News. Politico reported that two female employees complained of sexually suggestive behaviour from Mr Cain when he led a restaurant lobby group. It said the National Restaurant Association paid the women to leave the group and not speak on the allegations. Mr Cain told Fox News: "I've never sexually harassed anyone." "And yes, I was falsely accused while I was at the National Restaurant Association, and I say falsely because it turned out after the investigation to be baseless." He said he had no idea whether the trade association provided financial settlements to the women who complained. "If there was a settlement, it was handled by some of the other officers at the restaurant association," he said. 'Witch hunt' The National Restaurant Association said it did not comment on personnel matters. Mr Cain kept to his campaign schedule on Monday. He did not discuss the issue when addressing the American Enterprise Institute in Washington DC about tax reform. But later in the day, he told the National Press Club in the city the allegations were "totally false" and a "witch hunt". His campaign also denied the reports. "Let me tell you that Herman Cain has never sexually harassed anybody, period. End of story," Mr Cain's chief of staff, Mark Block, told MSNBC on Monday morning. Mr Block said top officials at the National Restaurant Association thought Mr Cain was "a man of total integrity". A statement on Sunday attacked the story. "Dredging up thinly sourced allegations stemming from Mr Cain's tenure as the chief executive officer at the National Restaurant Association in the 1990s, political trade press are now casting aspersions on his character and spreading rumours that never stood up to the facts," spokesman JD Gordon said. The Cain campaign also responded on Twitter. "From Team HC: Sadly we've seen this movie played out before. Mr. Cain and all Americans deserve better," @THEHermanCain tweeted. 'Sexually suggestive' Mr Cain, who was CEO of Godfather's Pizza before heading the restaurant lobby group, has taken a lead in opinion polls of Republican voters in recent weeks, despite never having held public office. Politico said it had confirmed the identities of two former female employees of the National Restaurant Association who made sexual harassment complaints to colleagues and association officials about Mr Cain, but was not publishing their names out of concerns for their privacy. The website said the allegations included conversations "filled with innuendo or personal questions of a sexually suggestive nature" at association events. Mr Cain also allegedly gave "descriptions of physical gestures that were not overtly sexual, but that made women who experienced them or witnessed them uncomfortable". Politico said its report was based on multiple sources and documentation, including the recollections of close associates of the two women. When asked by Politico on Sunday about the allegations, Mr Cain said he has "had thousands of people working for me" at different businesses over the years and could not comment "until I see some facts or some concrete evidence". A poll on Saturday placed Mr Cain ahead of his main rival, former Massachusetts Governor Mitt Romney, in Iowa, which holds the first of a series of state-by-state contests to choose the Republican candidate. The hopefuls are vying to become the party's nominee to challenge President Barack Obama for the White House in November 2012.