An Interpol red notice was issued on Thursday for fugitive Briton Samantha Lewthwaite -- dubbed the "white widow" -- who was allegedly involved in an attack at a mall in Nairobi, Kenya.

The International Criminal Police Organisation (Interpol) said the red notice, which is an internationally wanted person alert, was issued at the request of Kenyan authorities.

"By requesting an Interpol red notice, Kenya has activated a global 'tripwire' for this fugitive," Interpol secretary general Ronald K Noble said in a statement.

"Through the... red notice, Kenyan authorities have ensured that all 190 member countries are aware of the danger posed by this woman, not just across the region, but also worldwide."

She was wanted by Kenya on charges of being in possession of explosives and conspiracy to commit a felony, dating back to December 2011.

In another statement, released on Thursday evening, Interpol clarified the objective of the notice, saying Interpol officers were not sent to arrest individuals who were the subject of the notice.

"In cases where arrests are made based on a red notice, these are made by national police officials in Interpol member countries.

"Interpol cannot demand that any member country arrests the subject of a red notice. Any individual who is subject to an Interpol notice should be considered innocent until proven guilty."

A picture of a South African passport with Lewthwaite's photo and the name Natalie Faye Webb was distributed by Kenyan police.

Home Affairs Minister Naledi Pandor said the passport was fraudulently acquired.

"It [the passport] was investigated and reported on in 2011. It was cancelled at the time as it was found to be acquired fraudulently," she told reporters in Pretoria.

Pandor said further investigations had to be done into the acquisition of the passport and how it was issued.

"What we need to do is look at the applications office and check who processed it and how that person met the requirements to be granted a passport."

Noble said Lewthwaite's case underlined the "invisible threat" posed by terrorists using illicit passports.

"Every year hundreds of millions of individuals are boarding international transport and crossing borders without having the authenticity of their travel or identity document checked," he said.

"This dramatically compromises our ability to effectively screen and identify at airports and land crossings those individuals who could be suspected criminals and terrorists."

The 29-year-old woman was nicknamed the "white widow" after the death of her husband Germaine Lindsay, who was one of the four bombers involved in the July 7 attacks in London in 2005.

Al-Qaeda affiliated group Al-Shabaab has claimed responsibility for the attack at Nairobi's Westgate mall on Saturday.

Attackers were at the mall for four days in a siege in which at least 67 people were killed.

It has been speculated that Lewthwaite was involved in the attack.

Interpol said it had deployed a team to Nairobi to help co-ordinate the international response in the Kenyan investigation.