MADRID, Spain (CNN) -- Spain has again seized an American treasure-hunting ship over a dispute with its owners over who has rights to millions of dollars worth of booty recovered from the sea, officials said.
Police watch as the "Odyssey Explorer" is led into the Spanish port of Algeciras.
Spain seized the "Odyssey Explorer" -- owned by Odyssey Marine Exploration based Tampa, Florida -- as it sailed out of port in the British colony of Gibraltar on Tuesday.
Armed Spanish government vessels were waiting for the Explorer when it reached 6.4 kilometers (4 miles) off Gibraltar's shore and entered what Spain considers its territorial waters.
But Explorer's captain, Sterling Vorus, told the Spaniards he considered his ship to be in international waters, Odyssey owner Greg Stemm told CNN.
The Spanish vessels forced the Explorer to dock at Spain's nearby port of Algeciras, a Civil Guard spokesman told CNN. Stemm said the ship went to port only "under the threat of deadly force."
Once in Algeciras, Explorer's captain refused to allow Spanish officials to board the ship for an inspection, pending approval of the Explorer's flag state -- the Commonwealth of the Bahamas -- which Stemm said is required by international and Spanish law.
But Spain arrested the captain for disobedience and he spent Tuesday night in a Spanish jail, the spokesman said. He was released Wednesday, Stemm said.
Officials began the inspection soon after the captain's arrest. Stemm said Wednesday that he didn't know if the inspection had concluded.
Spain "intercepted and seized" the Explorer on Tuesday under a court order on "suspicion that Odyssey, through its ships, is recovering Spanish maritime heritage, in Spanish waters, without authorization," the spokesman said.
It is the second time in four months that Spain has seized an Odyssey vessel as it sailed off of Gibraltar. Last July, another Odyssey ship Alert was ordered to port, searched for three days and eventually released, Stemm said.
Before Tuesday, Spain had filed suit in Tampa against Odyssey, laying claim to at least some of the estimated $500 million in gold and silver pieces that its crew recovered from the sea near Spain in May. The coins were then flown from Gibraltar to Florida for safekeeping.
Spain considers that loot could be Spanish coins, at the least, and possibly from a Spanish ship. Odyssey, in announcing that discovery -- which is thought to be one of the biggest undersea treasures ever recovered -- did not publicly disclose the location, instead nicknaming the site "Black Swan."
Stemm has said the secrecy was needed to prevent the site being plundered by others.
"I hope that authorities come to realize that Odyssey has done everything to the letter -- and spirit -- of the law," Stemm said by e-mail in response to CNN. "The real criminals here are the people that are spreading false and misleading information about Odyssey to suit their own agendas."
"I don't blame the Spanish Guardia Civil and the navy," Stemm added. "They are just following orders. But it would be nice if the people giving those orders would do some due diligence and realize that the issue of the Black Swan is being handled by a U.S. federal court judge, and all this drama means nothing to the judge."
About a dozen journalists from the United States, Britain, Spain, Germany and France were aboard Explorer on Tuesday, and Spanish authorities took their video tapes, tape recorders and computer memory storage devices once the ship reached port, Stemm said.
A reporter for Spain's El Pais newspaper, among those onboard, reported that Civil Guards said that seizure of journalists' material was on orders from the Spanish judge. The Civil Guard spokesman said he could not confirm that report. E-mail to a friend