By Alex Crawford, Special Correspondent, In Kenya
Sky News has obtained a Kenyan intelligence report which for the first time shows the reach of the al Shabaab terror network - which carried out the Nairobi shopping mall attack - and the extent of British involvement within the group.
It suggests that Samantha Lewthwaite - the British woman known as the 'White Widow' because she was married to one of the 7/7 London bombers - is an important figure in the terror outfit, plotting multiple bomb attacks across Kenya.
Sky has also been given access to a personal diary of hers which gives a fascinating insight into her mind, where she talks about her ambitions for her children and her love for her husband.
The intelligence report, which is 35 pages long, gives a detailed breakdown of how the network is operating throughout Africa with recruits and cells working in a huge range of countries including Somalia, Uganda, Burundi, Zambia, Tanzania, Mali and South Africa as well as further afield in Yemen and Pakistan.
The report says Lewthwaite is a 'logistician' in a six-person terror cell
But what seems clear is that the group's stronghold and focus is in Kenya with major operational bases in the capital Nairobi and Mombasa.
The report is highly damaging for the Kenyan authorities as it also shows there were clear warnings up to eight months ago that a "Mumbai-style attack" was being planned in Nairobi on the Westgate shopping mall.
It goes on to identify 29-year-old Lewthwaite as a "logistician" within a six-person terror cell which the Kenyans believe was co-ordinated by Abdulkadir Mohamed Abdulkadir, whose alias is Ikrima.
Ikrima is a Kenyan who the authorities believe has been elevated to al Shabaab management.
He was the target of the US Navy Seals' mission last weekend which set out to "capture or kill" him from the Somalian port town of Barawe.
She is implicated in the Nairobi shopping centre attack in September
The mission was aborted when the Seals encountered tougher resistance than expected when they landed.
The other members of the terror cell Ikrima was co-ordinating include Fahmi Jamal Salim, who is apparently the cell leader and who the intelligence agencies believe is now married to Lewthwaite.
Other members are said to be Jermaine Grant, who is currently on trial in Mombasa on terror charges which he denies.
The report details how the group was plotting multiple attacks targeting the Kenyan parliament buildings, UN offices in Nairobi, restaurants and a string of assassinations focusing on senior politicians within Kenya.
Londoner Jermaine Grant is also believed to be part of the same group
Kenyan intelligence believes Lewthwaite was living in an exclusive villa in the Shanzu area of Mombasa when the attacks were being planned.
A police raid on a nearby apartment rented by Grant - which led to his arrest - then prompted a subsequent raid on the upmarket villa where Lewthwaite was living with her children.
But the mother-of-four was not there. The police say they found a stash of ammunition there as well as a laptop and excerpts of a diary or journal which Lewthwaite had begun writing.
Lewthwaite's husband Jermaine Lindsay (L) on a dry run for the 7/7 attacks
The journal appears to be the start of a book which Lewthwaite was working on entitled I Want To Be A Mujahid (Islamic military fighter).
It outlines questions she was going to pose to interviewees as well as gives an insight into her love for her husband and reveals a little about how she is bringing up her children.
She writes with pride about how two of her children want to emulate their father - Jermaine Lindsay, who was one of the London 7/7 bombers in the Tube and bus attacks in 2005 which killed more than 50 people.
She recounts how her husband had asked her children what they wanted to be when they got older.
Lewthwaite writes: "Both had many answers but both agreed to one of wanting to be a mujahid."
Extracts from Lewthwaite's diary recovered by police
She goes on to express her commitment and desire to be a good Muslim and how blessed she believes she is to have been married to a shaheed (martyr) in reference to her suicide-bomber partner.
We managed to persuade one of Kenya's most controversial religious scholars to sit down with us and talk about his views - which have led to him being accused by the UN of recruiting al Shabaab fighters and raising funds for the outfit.
Sheikh Abubakar Shariff, who is also known as Makaburi, told us the accusations against him were all "b*******".
Interpol recently issued a 'Red Notice' for Lewthwaite's arrest
He accused the Kenyan government of waging a religious war and allowing the persecution of Muslims who he believes are all being targeted and labelled as terrorists in the wake of the Westgate mall attack.
"Because of the failings of our Government and our military and police in stopping the attack, we, as Muslims, are all being targeted now," he told me.
Makaburi who is also accused by the Kenyan authorities of inciting violence and of encouraging young men to take up jihad (or Holy war) in Somalia, denied he was a member of al Shabaab but said: "I am a Muslim. I speak truthfully. I might have association with al Shabaab without me knowing they are from al Shabaab.
"I cannot say no, I don't know al Shabaab. Maybe one of my friends is a member of al Shabaab without me knowing. But do I have, what you call it, ties with al Shabaab? No, I don't."
He went on to say under his interpretation of the Koran, the Westgate attack was justified because of all the wrongs being meted out to Muslims by the West, the Kenyan Defence Force (who are fighting al Shabaab in Somalia), Ethiopians and other military in "Somalia, Guantanamo Bay, Iraq and all over the world every day".
There is little chance the woman being hunted by Interpol is still in Mombasa, but what the intelligence report indicates is it is now a major hub as well as gateway to terrorism for those bent on violence.