Popular Party spokeswoman Soraya Saenz de Santamaria said they want the director of the National Intelligence Center, Felix Sanz Roldan, to testify behind closed doors at parliament.

The Spanish trawler Alakrana was released Tuesday after an alleged ransom payment of $3.3 million. Somali pirates held the ship and its 36-member crew for 47 days.

The Spanish government refuses to say if a ransom was paid, although Prime Minister Jose Luis Rodriguez Zapatero has done little to deny it, saying the government "did what it had to do."

The Popular Party has refrained publicly from criticizing the alleged payment, but it has assailed the government's handling of the crisis.

"We want to know what happened in order to take measures and help in any way we can," Saenz de Santamaria said in a television interview. She was answering a question as to whether she thought the government or the ship's owner had made the reported ransom payment.

The party said Zapatero has ignored repeated calls from it and other parties for troops be stationed on Spanish fishing boats in the Indian Ocean after a series of hijackings or attempts over the past year, neglected the Alakrana sailors' distraught families during much of the ordeal and played up the conclusion of the crisis as a triumph for the government.

Defense Minister Carme Chacon told reporters that all Spanish fishing boats in the Indian Ocean have private security guards now. Ship owners have asked for Spanish troops instead. The government says Spanish law bars the military from being used to protect private property.

The Defense Ministry said another Spanish tuna boat in the Indian Ocean spotted pirate-style skiffs at a distance of several nautical miles Thursday but was not attacked.