Gianfranco Fini, the Italian Foreign Minister, increased a diplomatic row with the United States today by demanding that Washington identify and punish those responsible for the shooting of Rome’s top intelligence agent in Iraq.

Signor Fini dismissed the American version that a lack of communication was responsible for the death of Nicola Calipari, who died in a hail of gunfire from US troops as he escorted a freed Italian hostage to Baghdad airport on Friday.

Signor Calipari had made "all the necessary contacts" with US authorities in Baghdad, the minister said.

In his account to parliament of the shooting, which has sparked a diplomatic row with the US, Signor Fini said: "The reconstruction of the event does not coincide fully with what the American authorities have told us."

He said that the car carrying Signor Calipari and the freed hostage, Guiliana Sgrena, to freedom was not speeding and was not ordered to stop by US troops, as American officials have indicated.

He also dismissed as "groundless" a suggestion from Signora Sgrena, the hostage in question, that American forces had ambushed the car because they disagreed with Italy's policy of paying the ransom demands of Iraqi kidnappers.

Italy reportedly paid more than $6 million (£3.1 million) for Signora Sgrena's release, which was negotiated by Signor Calipari himself.

"The car was travelling at a velocity that couldn't have been more than 40 kilometres (25 miles) per hour," Signor Fini said.

Rejecting the ambush claim, Signor Fini said: "It was an accident. This does not prevent - in fact it makes it a duty - for the Government to demand that light be shed on the murky issues, that responsibilities be pinpointed, and, where found, that the culprits be punished.

"We ask for truth and justice."

The minister took pains to point out, however, that Italy has an "old and empathetic friendship" with the United States, adding: "We hope that that within the next few hours this affirmed wish for loyal co-operation will yield its first major concrete result.

"We hope that this is not an opportunity to whip up political campaigns and to sow anti-American sentiment in public opinion, which certainly have no reason to exist."

Amid an outpouring of patriotism, grief and anger, Italy gave an emotional state funeral yesterday to the dead intelligence officer as politicians united to demand "clear answers" from the United States.

The White House has voiced its regrets for the killing, but rejected as "absurd" claims from Signora Sgrena, a journalist for the left-wing newspaper Il Manifesto, that US troops had deliberately set out to kill her.

The funeral was held in Michelangelo’s church of Santa Maria degli Angeli. Earlier, 100,000 people had filed past the coffin at the Tomb of the Unknown Soldier.

Mel Sembler, the US Ambassador, joined Silvio Berlusconi, the Prime Minister, and Romano Prodi, the opposition leader, at the Mass. Officials comforted Signor Calipari’s widow, Rosa, and her two teenage children.

Thousands listened to broadcast tributes. "He died a hero," said Maurizio Agliana, one of three security guards kidnapped in Iraq last April and freed after secret negotiations by Signor Calipari.

The service brought into the spotlight senior anti-terrorist figures, including Gianni Letta, Signor Berlusconi’s chief of staff, and Niccolo Pollari, the head of the security service.

In his eulogy, Signor Pollari recalled the last phone call made to him by Signor Calipari as he approached Baghdad airport. He said that the agent was exuberant. " ‘Victory,’ he said to me. ‘Giuliana is here in the car with us. I’ll call you in a minute when we reach safety.’ But he did not call again. The rest we all know."

Signora Sgrena, who was held by kidnappers for a month, did not attend the funeral. She is in a Rome hospital recovering from a shrapnel wound to her shoulder.

Washington said that the shooting was an accident in which troops opened fire because they had not been told of the rescue mission and the Italians’ car failed to stop.

The shooting is said to have especially angered Signor Berlusconi, who sent 3,000 Italian troops to Iraq despite widespread opposition in Italy.

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