Man who's kept Santorum in the saddle kicks up a controversy

Foster Freiss, pictured with wife Lynn, is a close Santorum adviser (Getty Images)

He's a billionaire businessman and conservative evangelical Christian and the latest in the spotlight in the Republican presidential race. But although he has all the credentials to be a candidate he's not one.

Foster Friess, a rancher who made his fortune in the mutual fund business, has been thrust into the limelight since Rick Santorum emerged this week as the most potent threat yet to Mitt Romney in the race for the Republican presidential nomination. Mr Santorum faces questions about his proximity to a billionaire donor from Wyoming with a long record of supporting the Christian right and its causes.

That Mr Santorum is still in contention may in part be due to the generosity of Mr Friess. Records show he gave a third of a million dollars to an independent group supporting Mr Santorum, called the Red, White and Blue Fund, before the end of last year. How much more money he has given since is not known.

After Mr Santorum's three-state sweep this week, his relationship with Mr Friess is suddenly under the microscope. Rewritten election laws make it possible for the very wealthy to influence the democratic process by writing cheques not to individual candidates themselves but to so-called "Super-PACs" that back them. Those groups and the candidates are forbidden to co-ordinate strategy, however.

Mr Friess and Mr Santorum appear to be a natural match. Like the candidate, the billionaire and his wife Lynn wear their faith on their sleeves. Visitors to his website will quickly learn: "Lynn and Foster gain their philanthropic inspiration from Galatians 6:2: 'When we carry one another's burdens we fulfil the law of Christ', and Matthew 25:35-40, 'When you do it for the least of my brethren, you do it for Me'."

Mr Friess, 71, is also an outspoken foreign policy hawk. He may be one reason Mr Santorum has stood out in some of the debates for his aggressive language on Iran and the threat it poses to Israel. If more than an arm's length is meant to be maintained between the Super-PACs and the candidates, that is not the case between these men.

Mr Friess often travels with Mr Santorum on the election trail; he was on the stage when Mr Santorum gave his victory speech in Missouri on Tuesday night and will introduce him today at a conference of American conservatives in Washington.

Mr Santorum has done nothing to conceal the presence of Mr Friess in his inner circle of advisers. But he insists he talks with him about everything except the activities of Red, White and Blue, which would clearly be a violation of the law.

"Foster Friess does not run my Super-PAC," said Mr Santorum. "He may be a donor to it, but the people who personally run my Super-PAC, I haven't spoken with in about five months. So, no, I mean, as far as the conversations we have, Foster has been a long personal friend for 20 years."

He added: "I'm very, very fastidious about conversations I've had with him."

Mr Friess took a similar tack. "Basically, our lawyers have told us that it's very, very simple. You just don't talk about the Super-PAC," he told CNN. Pressed in an interview with The New York Times to reveal how much more money he had poured into the campaign, he again demurred. "If my wife finds out how much I put into the campaign and Santorum doesn't win, you're basically talking suicide," he replied.