Captors refused to back down despite message exchange

Frantic diplomacy was going on behind the scenes right up until the moment Ken Bigley was beheaded by his captors, the Foreign Secretary revealed for the first time last night. Jack Straw also revealed that the Government knew about Mr Bigley's death 24 hours before the news emerged via Abu Dhabi television.

Dialogue was started with the kidnappers after an intermediary contacted the British embassy in Baghdad, Mr Straw said. "Four days ago, an individual approached the British embassy in Baghdad, presenting himself as a potential intermediary with the captors. It was very clearly in Mr Bigley's interest that we should do all we could to establish contact," Mr Straw said.

"Messages were exchanged with the hostage-takers in an attempt to dissuade them from carrying out their threat to kill Mr Bigley. At no stage did they abandon their demands relating to the release of women prisoners, even though they were aware that there are no women prisoners in our custody in Iraq."

Mr Straw explained thatmessages sent to the kidnappers were endorsed by himself and the Prime Minister. He added: "Ken Bigley's family in Liverpool and his wife in Thailand were kept fully aware of our communications with this intermediary. This afternoon the intermediary has provided us with proof ... that Ken Bigley's captors have carried out their threat."

At a Foreign Office media briefing in Baghdad last night, it was suggested that negotiations with the hostage-takers had been going on for a lot longer than the past four days.

The Foreign Secretary said he "fully understood the grief of family members", but added: "We did everything we possibly could." Mr Straw rejected suggestions from Mr Bigley's brother Paul that more could have been done to save him. On Tuesday, Mr Straw visited Iraq where he met the Iraqi interim Prime Minister, Iyad Allawi, to discuss how to free the British hostage. Mr Allawi said his government was doing all it could to obtain the release.

On the same day, it also emerged that the Irish government had granted Mr Bigley a passport to prove his Irish heritage ­ his mother, Lil, is from Dublin. Ireland's neutrality enables it to play a useful role in such situations.

Mr Bigley's family were in contact with Irish politicians, who have been lobbying influential figures in the Middle East. Dermot Ahern, the Irish Foreign Minister, said he hoped that issuing Mr Bigley with an Irish passport would "contribute to the efforts to secure his release". But Mr Ahern added that there had been no secret deal with Whitehall to issue the passport.

Last Friday night, Bertie Ahern, Ireland's Prime Minister, made a television plea to the kidnappers, calling Mr Bigley an "ordinary working man" who did not deserve to be held.

Last month, two leading British Muslims, Daud Abdullah and Musharraf Hussain, travelled to Iraq to plead with local Muslim leaders and politicians on Mr Bigley's behalf.

Leading figures from the Arab world also tried to secure his release. Several Middle Eastern leaders were also at the heart of the tortuous diplomatic efforts. On Tuesday, Saif Gaddafi, the son of Colonel Gaddafi, offered help saying that his father was willing to put up money to help free Mr Bigley. He added that his charity foundation was in contact with intermediaries in Iraq.

At the end of last month, it also emerged that the Palestinian leader, Yasser Arafat, had tried to help.

THE LONG REACH OF ZARQAWI

Jordanian-born Abu Musab al-Zarqawi has become synonymous with murdering hostages, as well as a wave of suicide attacks that have claimed dozens of lives. The US has repeatedly said he has links with al-Qa'ida and Osama bin Laden.

Zarqawi, 37, has earned a place in the American lexicon of enemies alongside Bin Laden, Saddam and Mullah Omar. The US has put a $25m (£14m) bounty on his head, the same amount as Bin Laden. It rose from $5m along with the scale of his activities.

What has given a particularly dark lustre to his image is that he not only directs terror, but is also said to personally take part and revel in it. US intelligence says voice recognition tests show that it is Zarqawi who makes exultant statements after carrying out many of the decapitations.

Zarqawi is someone whom others in the resistance have become wary of. Clerics who have criticised his methods, especially taking hostages, have been murdered.

A veteran of the Afghan war, last year he gained recognition when the US Secretary of State, Colin Powell, named him as a link between al-Qa'ida and Saddam - a charge which has since been discredited. It did, however, give him the credibility to set up the Tawhid and Jihad group.