BAGHDAD, Iraq – A weeping British hostage was shown pleading for help between the bars of a makeshift cage in a video that surfaced yesterday, a sobering reminder of the grim reality for at least 18 foreign captives still held by Iraqi terrorists.

There is wide speculation that ransoms were paid for the freedom of a dozen hostages, including two Italian aid workers.

The new footage, first broadcast on the Arab news network Al Jazeera and then posted on the Internet, showed Kenneth Bigley begging Prime Minister Blair to meet his captors’ demands.

“Tony Blair, I am begging you for my life,” the 62-year-old Mr. Bigley said between sobs. “Have some compassion. Only you can help me now.”

He accused Mr. Blair of lying about efforts to secure his release, saying no negotiations were taking place.

“My life is cheap. He doesn’t care about me. I am just one person,” the civil engineer said. “I want to go home. Please, Mr. Blair, don’t leave me here.”

It was the second tape in a week to surface showing Mr. Bigley appealing for help. Iraq’s most feared terror group, Tawhid and Jihad, beheaded two American hostages seized with Mr. Bigley and warned he will be the next to die unless Iraqi women prisoners are freed.

Gruesome videotapes of the killings were posted on the Internet, and the men’s decapitated bodies were found in Baghdad – not far from the upscale neighborhood where they were seized from their house September 16. In the latest tape, Mr. Bigley sat hunched on the floor of a cage, his hands and legs in chains. He was dressed in an orange jumpsuit, similar to those worn by Americans Eugene Armstrong and Jack Hensley when they were slain. The leader of Tawhid and Jihad, Jordanian terror mastermind Abu Musab al-Zarqawi, personally beheaded Armstrong.

Asked to respond to Mr. Bigley’s plea, Mr. Blair said yesterday evening, “I feel absolutely sick about what has happened and I feel desperately sorry not just for Ken Bigley, obviously, but for the whole of his family.”

He said the government was doing everything it could to help Mr. Bigley and would respond if his captors initiated contact, but had no way to reach them. Mr. Bigley’s brother, Paul, told the British Broadcasting Corp. that the images of his brother chained and caged were “absolutely appalling, there’s no other word for it, heart wrenching.” But he said he was pleased to see his brother alive.

“That’s the good news I see through the smoke,” he said. “This is a last ditch attempt, something has to be done and something has to be done very quickly.”

More than 140 foreigners have been kidnapped in Iraq and at least 26 have been killed. Some, like Mr. Bigley, were seized by insurgents as leverage in their campaign against the United States and its allies. But others were taken by criminals seeking ransom.

“This kind of thing creates a broader contagion for people suffering for other reasons under the occupation,” said Jonathan Stevenson, senior fellow for counterterrorism with the International Institute for Strategic Studies in Washington. “They get the idea that they can earn some extra cash by kidnapping people.”

Mr. Stevenson said Mr. al-Zarqawi and his followers probably realize they can’t drive America and Britain out of Iraq. But terrorists hope that by taking hostages, they can force the release of a few Iraqi prisoners or the pullout of some troops – the Philippines withdrew its 51 soldiers to free a captive – allowing them to declare victory.

The back-to-back releases this week of the two Italian aid workers and four Egyptian communications engineers raised questions about whether ransoms were paid to win their freedom.