Ehmed Chisty says he organised the documents for Lewthwaite, which she is suspected of using to set up home in Johannesburg.
Lewthwaite was named last week by Interpol as the world's most wanted women following the Nairobi mall massacre and it has now been claimed she may have worked with a second jihadist from Britain in plotting the attack.
A copy of Samantha Lewthwaite's fake South
African passport. Forger Ehmed Chisty claims she paid him £1,200 for
false passports for herself and two of her children
Lewthwaite is pictured, right, in the South
African passport photograph and, left, in a picture from a personal
computer found by police at the house she was renting in Mombasa
Umar Arshad fled Britain six years ago and has now reportedly risen up the Al Qaeda ranks and has been named in connection with the Westgate atrocity.
Six Britons were among at least 67 people murdered by Al Shabaab terrorists at the upmarket mall
Muslim convert Lewthwaite, 29, is the widow of 7/7 suicide bomber Jermaine Lindsay.
She fled her home in Aylesbury, Buckinghamshire, in 2009, and is on the run in East Africa.