Numerous mechanisms have been adopted to curb the fraudulent issuing of documents by dishonest home affairs officials, director general Mkuseli Apleni said on Thursday.

"To fight the scourge of corruption within the department, we had to implement systems which are able to uniquely identify who is this person [official] and who is doing what," he told reporters in Pretoria.

The department had installed biometric fingerprint readers for staff to access its systems, he said.

"The department has been successful in dealing with people who are committing fraud. Every month we report when there are people arrested in the department either at the ports of entry or within the department."

Apleni said the new system enabled home affairs management to trace every document it produced.

"Whoever in the department commits crime, we are able to identify those individuals."

Apleni said the security of the South African passport had not been brought into question with the link to Kenyan terror suspect Samantha Lewthwaite. She reportedly acquired a South African passport in 2011.

"We changed our passport. Its security features were weak and were able to be falsified. The minister (Naledi Pandor) has indicated that it was not the passport which was faked, it was the process of obtaining that passport [by Lewthwaite]," he said.

The circumstances surrounding the fraudulent acquisition of the South African passport by Lewthwaite, who has been dubbed the "White Widow" by the British media, were being investigated.

"This matter is being investigated, but not by the department of home affairs only. It is being investigated by the JCPS [justice, crime prevention, and security] cluster," he said.

"Once they are finalised, the public will be informed."

He said several law enforcement agencies were gathering information about Lewthwaite. She was allegedly involved in an attack on shoppers at the Westgate mall in Nairobi, Kenya, on September 21, in which 67 people were killed.

The government was investigating reports that Lewthwaite may have travelled to Kenya on a South African passport in the name of Natalie Faye Webb.

Last week, home affairs spokesperson Ronnie Mamoepa said South Africa would work with the Kenyan authorities to obtain a copy of the passport to determine the facts.

Lewthwaite was reportedly a regular visitor to the country and used the South African passport as one of a number of aliases whenever she travelled.

Apleni said the Public Protector had cleared the department of any irregularity and maladministration in the appointment of a service provider during the relocation of its headquarters from Waltloo, east of Pretoria, to the Hallmark building in the city centre.

He said the move was in line with the government's policy of locating all government buildings in the city centre, to boost confidence in the capital city.

"No irregular appointment by the department was found and the matter is consequently and hereby closed."