TEHRAN, Iran (AP) – The sudden release of an Iranian diplomat missing for two months in Iraq raised new hope Tuesday that 15 British sailors and marines seized by Iran may soon be freed.

It also suggests the standoff over the captive Britons may end with a de facto prisoner swap – something both Tehran and London have publicly discounted.

Diplomat Jalal Sharafi arrived in Tehran on Tuesday, hours after he was freed by his captors in Iraq, officials said. He was seized Feb. 4 by uniformed gunmen in Karradah, a Shiite-controlled district of Baghdad.

Iran alleged the diplomat had been abducted by an Iraqi military unit commanded by American forces – a charge repeated by several Iraqi Shiite lawmakers. American authorities denied any role in his disappearance.

In Baghdad, an Iraqi Foreign Ministry official said the Iraqi government had exerted pressure on those holding Mr. Sharafi to release him – but he would not identify who had held Sharafi.

But another senior government official said Iraqi intelligence had been holding him. Both officials spoke on condition of anonymity because they were not supposed to release the information.

Mr. Sharafi was a second secretary at the Iranian Embassy involved in plans to open a branch of the Iranian national bank. American officials allege that Iran provides money and weapons to Iraqi Shiite militias.

Mr. Sharafi was abducted a month after the American military arrested five other Iranians in northern Iraq. America described one of those captives as a senior officer of the Quds Force, an elite unit of Iran’s Revolutionary Guards.

The Iraqi Foreign Ministry official said his government also was working “intensively” for the release of the five other Iranians to “help in the release of the British sailors and marines.”

Neither Iran nor Iraq nor Britain has said explicitly that a prisoner swap was in the works. Iran has denied it seized the Britons to force the release of Iranians held in Iraq, and Britain has steadfastly insisted it would not negotiate for the sailors’ freedom.

In Washington, President Bush signaled the same. “I also strongly support the prime minister’s declaration that there should be no quid pro quos when it comes to the hostages,” Mr. Bush said.

It was unclear whether the Iraqis had won Mr. Sharafi’s freedom on their own initiative to encourage a settlement, which would ease tension without endangering their own claim to the waters where it occurred.

Nevertheless, the release of Mr. Sharafi and efforts to free the five other Iranians suggested that the parameters of a deal might be taking shape.

Iran maintains the British sailors had encroached on Iranian territory when they were seized by naval units of the Revolutionary Guards on March 23. Britain insists its sailors and marines were in Iraqi waters and has demanded their unconditional release.

British Prime Minister Tony Blair told reporters in Scotland that the next two days would be “fairly critical” to resolving the standoff over the navy crew, although he gave no details what he meant.

Iran’s official Islamic Republic News Agency quoted First Vice President Parviz Davoodi as saying that “Britain should accept that it has invaded Iranian waters and guarantee that it will not be repeated.”

“The violation was clear and obvious and all evidences and documents were suggesting occurrence of the violation,” Mr. Davoodi added. “Britain has recently changed its approach and shifted toward legal and diplomatic negotiations.”

However, British Foreign Secretary Margaret Beckett urged caution in expectations of a swift resolution, saying that “diplomatic efforts will continue.” She also said Britain still has not been granted consular access to the captives.

With the standoff at a sensitive stage, Britain reacted with caution to the release Tuesday of new pictures of the British captives on the Web site of Iran’s Fars News Agency. The images showed six sailors sitting on a carpet in a room, wearing blue, black and red tracksuits. Two sailors were shown playing chess.

The caption said: “British sailors are chatting and eating fruit, drinking coffee and playing chess. It seems that the sailors are satisfied with their situation, in which they are enjoying good conditions instead of working in a hard situation in the Persian Gulf.”

Faye Turney, the only woman among the captured, was shown without a head scarf. She had worn one in initial images released of the Royal Navy crew.

Britain has expressed outrage over the airing of earlier videos in which Ms. Turney and others “confessed” to violating Iranian territorial waters. The British also froze most diplomatic contacts with Iran and urged their European and Asian allies to step up pressure on Tehran to free the captives.

The latest pictures did not show any further confessions. And as tensions have escalated, the Iranians have appeared to back off somewhat.

On Monday, an Iranian state-run television station said all 15 Britons had confessed to illegally entering Iranian waters. But state-run radio said the confessions would not be broadcast because of what it called “positive changes” in Britain’s negotiating stance.

Chief Iranian negotiator Ali Larijani told Britain’s Channel 4 news on Monday that Iranian officials “definitely believe that this issue can be resolved and there is no need for any trial.”

Mr. Blair told Scotland’s Real Radio that if Iran wants to resolve the standoff with diplomacy, “the door is open.”

Britain has two options, Mr. Blair said.

“One is to try settle this by way of peaceful and calm negotiation to get our people back as quickly as possible,” he said. “The other is to make it clear that if that is not possible, that we have to take an increasingly tougher position.”

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