Kenya's President Uhuru Kenyatta.
A Briton arrested in Nairobi following the bloody attack on a shopping mall by armed Islamists is "not of significant interest" to the investigation, the British high commissioner said on Wednesday.
Christian Turner, Britain's top diplomat in Kenya, made the comments in Nairobi and they were confirmed to Agence-France Presse by a foreign office spokesperson in London.
The foreign office earlier confirmed the arrest but declined to say whether it was linked to the bloody siege on Westgate mall, in which 67 people were killed.
"We can confirm the detention of a British national in Nairobi and we are making contact to offer standard consular assistance," said a spokesperson.
Kenyan Foreign Minister Amina Mohamed said on Monday that a British woman was among the attackers, although this contradicted earlier statements from Kenyan officials who said they were all male.
Suspicious behaviour
The foreign office spokesperson in London said: "We are aware of these reports that a British national was among the terrorists and we're looking into them, but we are not going to speculate on that."
The Daily Mail newspaper reported on Wednesday that a 35-year-old British man was detained at passport control as he prepared to fly out of Nairobi on Monday afternoon.
He had apparently attracted attention because of bruising to his face, his dark glasses and suspicious behaviour.
Kenya President Uhuru Kenyatta announced an end to the 80-hour bloodbath in Nairobi late on Tuesday. Sixty-one civilians and six members of the security forces were killed.
Kenyatta said five attackers were killed and 11 suspects detained.
Alleged planning of the siege
Meanwhile, the Somalia-based militants who stormed the mall had a detailed plan and had hidden weapons at the scene beforehand, according to US officials cited by the New York Times on Wednesday.
According to the report, a hand-picked group of English-speaking fighters from al-Shabab, an Islamist rebel group, had trained for the assault in Somalia for weeks beforehand.
On Saturday, the group burst into the upscale Westgate mall in Nairobi armed with grenades and assault rifles and set about killing staff and shoppers.
An investigation is continuing, but according to the "US security officials" quoted in the Times's report, the assault had been meticulously planned in Somalia.
The group had blueprints of the mall and had hidden powerful belt-fed machine guns in one of the stores beforehand, perhaps with the help of a corrupt local employee.
Some of the militants appear to have brought a change of clothes so they could swap out of their military-style fatigues, drop their guns and escape hidden among fleeing civilians.
DNA tests
Spy agencies are awaiting results of DNA tests on slain and captured attackers to confirm if any were recruited from the United States, Britain and other places beyond Somalia.
Witnesses cited by the Times said that at least two of the attackers were women, amid reports that the gang could have been led by Britain's Samantha Lewthwaite.
Lewthwaite is the widow of one of the suicide bombers who struck in London in July 2005. – AFP