The Republican presidential hopeful, Rick Santorum, spoke at a Messianic Jews convention in 2010, it emerged this week.
Mr Santorum, who remains the main obstacle to Mitt Romney's chances of the party's nomination, is known for his conservative views on issues such as abortion, homosexuality and birth control, inspired by his devout Catholicism.
He has strong support among the party's core voters, but the revelation that he was paid to address a controversial Messianic Christian group is unlikely to boost his chances in the upcoming New York and California primaries, where a total of 267 delegates are at stake.
According to Politico, Mr Santorum accepted £3,700 to speak at an event hosted by the Messianic Jewish Alliance of America, a group that has been condemned by the Anti-Defamation League for teaching that "Jews should convert to Christianity".
