Officials in the Dominican Republic said Jorge Puello did not have a license to practice law in his native country, and The New York Times reported the Haitian judge might delay the group's release because of questions about the adviser's possible links to a human-trafficking case.
Puello has been a high-profile advocate for the jailed Baptists as they navigate the Haitian justice system. He also now is in apparent violation of Dominican law for failing to register with the local bar association or obtain a license, said Jose Parra, vice president of the Dominican Lawyers Association.
Parra said his organization was investigating the situation and might file a complaint with the Justice Department, which could pursue criminal charges.
Puello declined to comment in a brief telephone interview, saying he would be busy in court representing a U.S. firm seeking to establish a business in the Dominican Republic. He could not be located in court and did not return later phone calls.
The Web site for Puello Consulting says it has offered "full legal services" for businesses in the Dominican Republic and elsewhere since 2005. The site was taken down Friday for unknown reasons.
The New York Times first reported that authorities in El Salvador are investigating whether Puello is a man suspected of leading a trafficking ring in that country involving Central American and Caribbean women and girls.
The newspaper reported that police said his picture appeared to match that of a suspected trafficker.
Puello denied any connection to trafficking in an interview with the newspaper and said he had never been to El Salvador.
Police Commissioner Howard Cotto, deputy director of investigations for the Salvadoran national police, told The Associated Press on Friday that authorities would need to compare fingerprints before they could determine if Puello was the man being investigated.
Late Friday, the Times quoted Haitian Judge Bernard Saint-Vil as saying that before he can let the Americans out of jail he must learn more about Puello.
The judge previously recommended provisional release for the group while their case is investigated.
"I am working as fast as I can, but I must first understand Mr. Puello," the Times quoted the judge as saying Friday.