Explore Park developer Larry Vander Maten has raised the ire of the Ukrainian government -- and could potentially wreck a Virginia-based exchange program -- over his refusal to send three children home, according to the program's president.

Three orphaned Ukrainian girls -- ages 9, 11 and 13 -- came to Vander Maten's home for what was supposed to be a summer visit through Frontier Horizon, a Virginia Beach-based humanitarian organization. The children were supposed to go home more than a week ago with a Ukrainian guardian who made the trip with them. The guardian did return to Ukraine without the children, said Vincent Rosini, president and founder of Frontier Horizon.

Rosini said Wednesday he has been working with the U.S. State Department and the Ukrainian government to compel Vander Maten to send the children home.

"I have no doubt he has the best intentions of the kids in mind, but he's ruining our program," Rosini said, adding that Vander Maten "is breaking Ukrainian law by keeping the kids. It's just unbelievable."

Rosini's agency normally brings orphans from Ukraine to the United States for a two- to three-week holiday with host families. In some cases, such as Vander Maten's, children may stay longer if they already have a relationship with a family.

Rosini said Vander Maten's family, which lives near Orlando, Fla., met the three girls on a previous mission trip to Ukraine. The family later used Frontier Horizon to arrange the visit to Florida for the summer.

Vander Maten, whose plans for a "Blue Ridge America" vacation resort at Roanoke County's former Explore Park have been sidetracked by the economic downturn, did not return phone calls seeking comment. No one could be reached for comment, either, at the Ukrainian Embassy in Washington.

"A deputy minister [from Ukraine] told me there will be no more hosting for our program. So ours may be ruined," and other similar programs put in jeopardy, Rosini said.

An Orlando TV station reported Tuesday that Vander Maten wrote that one of the children was too sick to fly when they were due to return home, and then three days later, Vander Maten filed a guardianship request in a Florida court.

Rosini said Vander Maten has also hired an attorney in Ukraine in his attempt to become the children's guardian, but that he was turned down by a court there.

Rosini said in his nine years of running the Frontier Horizon program, which brings up to 90 children at a time to visit the United States and Canada, he's never encountered a similar situation.

"Every family is sad when the kids leave," he said, and many do end up eventually adopting the children they've kept or other ones from Ukraine, something his agency encourages. "But they do it the legal way."

"Larry for some reason decided to do this against others' wishes," Rosini said. "He's a guy who's used to getting what he wants, he's so wealthy and powerful, and he's going to court" to try to get the children.

Rosini said he has sent e-mails to Vander Maten "begging him to please consider what he's doing to me and the other families," but Vander Maten just writes back a one-sentence response: "Refer them to me."

Rosini said he's contacted Vander Maten's church and that other host families have sent "hundreds of e-mails to his house ... begging him to return the children."

"We're on the verge of an international incident," Rosini said.