Government officials declined to comment on Wednesday about reports that a woman linked to the Nairobi mall attacks rented property in Johannesburg and had a fake South African passport.
"I am not commenting on the matter," said Home Affairs spokesman Ronnie Mamoepa, to whom international department spokesman Clayson Monyela was referring all media inquiries.
ENews Channel Africa (eNCA) reported that a British citizen, Samantha Lewthwaite, who was wanted by Kenyan police for her alleged involvement in a separate terror plot, had used the name Natalie Faye Webb to rent at least three properties in Johannesburg and run up debts of R183,123.
The 29-year-old woman, who is nicknamed the "White Widow" because her husband was among the 2005 London suicide bombers, signed rental leases around Johannesburg, but it was unclear whether she lived at any of the properties.
The Hawks unit also declined to comment when asked if she was being investigated. Spokesman Captain Paul Ramaloko said it was "not at liberty to comment on what is happening in Kenya".
However, he confirmed that it was investigating the activities of the Somali militant group, al-Shabab.
"We do have a project that we are working on relating to the activities of al-Shabab," he said.
The Associated Press reported that al-Shabab is the Somali militant organisation that has claimed responsibility for this weekend's attack on the Westgate Mall in which 61 civilians, six security officers and five attackers died.