By Gordon Corera
BBC security correspondent
While the Muslim Council of Britain has been working on the ground in Baghdad to contact those holding British hostage Ken Bigley, more radical Islamists in London have been making their own efforts.
Mr Bigley was kidnapped with two Americans on 16 September
One figure, Yasser al-Sirri who runs the Islamic Observation Centre in London, says he received news over the weekend regarding Mr Bigley.
Mr al-Sirri told the BBC that he sent an email appeal though an intermediary in Iraq last Thursday and then received a number of messages back over the weekend including one indicating that Mr Bigley was alive and that Mr al-Sirri's appeal would be taken into account when determining the British hostage's fate.
On Sunday, Mr al-Sirri made appearances on the al-Arabiyah and al-Jazeera TV stations to make further appeals.
"We asked the group in our appeals to release the hostage as a gesture of generosity, particularly after Blair and his government let him down," he said.
The potential significance of this lies in the content of Mr al-Sirri's message as well as his background.
His lengthy original appeal was based on detailed arguments surrounding Islamic law, quoting from the Koran.
But his message also had a political context: "let his release be a clear message from you to the British people, and a call for them to realize the impotence and criminal nature of their government," Mr al-Sirri said.
He argues that Tony Blair has let Ken Bigley down by not securing his release and therefore by showing mercy to Mr Bigley, Mr al-Zarqawi could embarrass Mr Blair.
He also argues that Mr Bigley is merely an ordinary worker and that it would have more of powerful impact to release him.
"Show mercy to the weak. ... Let his release be a message to the British people to prove that Islam is a religion of forgiveness," read the appeal.
A similar appeal has also been made by another Islamist in London, Saudi dissident Dr Muhammad al-Masari who runs the Party for Islamic Renewal.
He told the BBC that though contact has been difficult and "haphazard", he has been able to talk over the phone to militants in Iraq.
Of course, it is impossible to know whether the messages Mr al-Sirri received back are valid since the contact is indirect.
But he is known as a figure with extensive links and credibility amongst more radical Islamists.
His Islamic Observation Centre monitors arrests and deportation of Islamists around the world.
Mr al-Sirri himself was sentenced to death in absentia in an Egyptian court in 1994 for his role in an assassination attempt on the Egyptian prime minister and he successfully fought off an attempt by the US to extradite him for links to terrorists.
A British judge also cleared him of conspiracy in the 2001 murder of Afghan General Ahmad Shah Masood in Afghanistan.
His background makes it more plausible that he could be able to get in contact with Zarqawi's group and, if he did, that his appeals would have more impact, although ultimately it is hard to be sure how significant the impact of these less mainstream Islamist voices will end up being in Ken Bigley's fate.