Three days after Bob Vander Plaats endorsed Rick Santorum for president, the evangelical leader has become mired in charges that he illegally solicited money from Santorum's campaign to promote the endorsement.

Santorum told CNN that before Vander Plaats -- the president of The Family Leader, an influential Christian conservative group in Iowa -- announced his endorsement on Tuesday, he called Santorum and said that he needed money to promote the endorsement, and that [it] would be important to do that.

Santorum emphasized that Vander Plaats did not request money specifically from Santorum's campaign -- There was never a direct ask for me to go out and raise money for it, he said -- but that has not stopped a flood of questions about whether Vander Plaats violated campaign finance laws, which prohibit any coordination between a campaign and an outside group.

The simple fact that they've had conversations does not establish any violation of laws dealing with coordination, Paul Ryan, a lawyer at the Campaign Legal Center, told The Des Moines Register. But coordinating expenditures on advertising could violate federal law.

It is unclear whether Vander Plaats and Santorum did, in fact, coordinate expenditures.

Vander Plaats has already recorded robo-calls praising Santorum, which were paid for by a political action committee called Leaders for Families. A spokesman for Santorum, Hogan Gidley, said in a statement that Santorum had not raised money for the PAC, insisting, We did not, nor would we ever agree to raise a single penny for another entity.

Vander Plaats himself told The Des Moines Register that there was absolutely no quid pro quo involved in his endorsement or the endorsement of Family Leader board member Chuck Hurley. He said that he and Hurley were working hard to raise money to promote the endorsement, but that he did not expect Santorum to provide that money or to help raise it.

We would never ask a candidate -- and by the way, when you endorse Rick Santorum, you probably should also know that you're not asking for $1 million, he told CNN. We would never ask a campaign or a candidate for funds, especially when you do a personal endorsement.

His and Hurley's endorsements were not made on behalf of The Family Leader, which chose to remain neutral.