A Moroccan who was one of the prime suspects in the Madrid train bombings once told a police informant that he wanted to blow up Madrid's biggest soccer stadium because "Spain needed a lesson," a paramilitary officer testified to a parliamentary commission on Tuesday.

A Civil Guard officer identified only as Agent Victor said that on March 16, shortly after the bombings, his Moroccan informant Rafa Zohuier called him to say Jamal Ahmidan (search) had once told him he wanted to blow up the Real Madrid (search) team's Santiago Bernabeu (search) stadium because of Spain's support for the U.S.-led invasion of Iraq.

Ahmidan, a Moroccan, allegedly bought the explosives that were used in the Madrid attacks, which killed 191 people on March 11. He was one of the suspects who blew themselves up in an apartment on April 3 as special forces prepared to storm it.

Islamist militants with possible links to Al Qaeda are blamed for planting 10 backpack bombs on four commuter trains in the attack, which also wounded some 1,600 people.

The conversation between Agent Victor and Zohuier was described in one of the documents presented to the commission Tuesday by Judge Juan del Olmo, who is investigating the attacks.

"It's true," Agent Victor told the parliamentary commission when asked about the conversation in the documents. "At that moment we believed that he knew people [linked to the attacks] and we immediately gave the information to the Civil Guard terrorism department," the officer said.

He added that Zohuier called him because he recognized other suspects close to Ahmidan whose photos appeared in newspapers and wanted to provide police with information.

"He thinks that the Chinese [nickname for Ahmidan] is the main person behind the attacks," officer Victor is quoted as saying in the documents. "Once he told him [Zohuier] that because Spain entered the conflict in Iraq he would love to blow up the Bernabeu to give Spain a lesson."

Three days after Agent Victor's conversation with Zohuier, Zohuier was detained. He was charged with collaboration with a terrorist group and is in jail.

The officer said that earlier in his frequent contacts with the informant, he never suspected Zohuier could have been connected to the attacks.

It was Zohuier who a year earlier had tipped off the police that someone in northern Spain was looking to sell a large quantity of explosives. The explosives were later believed to have been used in the bombings.

"At the very moment after the bombings, we didn't link the information from a year ago to what happened on March 11," Agent Victor told the commission on Tuesday.

Earlier, his boss told the commission that last year they had received a sample of the stolen explosives but dismissed it as being of poor quality.

"Nobody, not even the most perverse mind, could have imagined that the explosives ... could be used for something like March 11," a Civil Guard officer, identified only as Capt. Paco, told the commission.

"The explosive was of very poor quality and out of date," he said. "This maybe led us to believe that the information was not very urgent.

Police say there has long been a thriving black market in Spain for small amounts of stolen explosives, mostly for such uses as illegal land development.

Zohuier and a Spaniard, Emilio Suarez Trashorras, were police informers on cases involving drugs, explosives and weapons trafficking. They admit having dealt with the suspected attackers but say they thought the explosives were for use in mining in Morocco.