(CNN) -- A Colombian man, possibly linked with paramilitaries there, may be the mastermind behind the kidnapping in Venezuela of major league catcher Wilson Ramos, Venezuelan Justice Minister Tareck El Aissami said Saturday.
Authorities have identified him and an arrest warrant is being issued, he said.
Six Venezuelans have been arrested in the case, and more arrests are possible as the investigation continues, El Aissami said.
Ramos was rescued Friday night after a shootout between his suspected captors and rescuers in the mountainous region of Montalban, about 60 miles from the north central Venezuelan city where he was last seen.
He is healthy and unharmed, authorities said.
After the suspected captors opened fire on authorities, "we responded in a proportional way, but not in a way that would put at risk (Ramos') rescue," El Aissami said at a news conference.
The minister praised the bravery of the national guard troops who participated in the operation, singling out one guardsman who was under fire for several minutes "but did not retreat."
The day after Ramos went missing, investigators found the SUV used in the kidnapping, but had few clues to lead them to the perpetrators, he said.
So investigators focused on intelligence work -- matching the description of the snatching to the modus operandi of known criminal groups -- and eventually located a home where they believed Ramos was held.
Venezuelan President Chavez himself authorized the operation on the house, which included using helicopters to deliver the rescue team near its target, El Aissami said.
This house was, the team learned, a logistical base used by the kidnappers. According to the minister, it was the place where food and other logistics were prepared and then transferred to another location, where Ramos was actually being held.
The owners of the home, Lesbia Quesada, 60, and Aristides Sanchez, 64, were accused of being accomplices to the crime and were arrested, he said.
The rescue team then learned of a second home in an isolated area where Ramos was believed to be hiding. The trek there took three hours for the rescue team, as there were parts they could traverse only on foor, El Aissami said.
When they neared the second target, they were met with gunfire, and, according to the minister, that's how they knew Ramos was inside.
Authorities arrested Alexander Sanchez, 27; Francisco Finamor Penna, 20; Yosnar Cubillan, 21; and Anyuli Tarazona, 22.
But it was a Colombian man, possibly linked to paramilitaries, who gave the orders, El Aissami said. This man identified Ramos, got the information on his home, located his relatives and gave the orders to carry out the kidnapping, El Aissami said.
Ramos was full of thanks to his rescuers and his supporters upon his arrival at his family home in Venezuela early Saturday.
"I am very happy for the rescue operation they carried out. Very thankful to the government and the national army," Ramos told reporters.
"I didn't expect them. Where they were holding me captive was a very remote place, basically a jungle, and see, I was praying to God to bring me home safely to my family and look at these guys, they risked their lives to save mine and I am very thankful."
Ramos, a rising star for the Washington Nationals as a rookie this past year, was in his native country to play in Venezuela's winter league.
Washington Nationals officials applauded the news of his rescue.
"I am happy to announce that I have spoken directly with Wilson and he assures me he is unharmed," said Mike Rizzo, the team's general manager. "He asked me to thank all who played a role in his rescue, and all those who kept him and his family in their thoughts and prayers."
Ramos, 24, emerged as the team's top catcher this past season. He had a .267 batting average with 15 home runs and 52 runs batted in.
Though soccer reigns in most Latin American countries, baseball rules in Venezuela, which routinely feeds players to major league teams in the United States.