"The assessment of the complaint is still underway. It includes interviewing identified witnesses," said Public protector Thuli Madonsela's spokesperson Oupa Segalwe.
"It is only after this assessment that the public protector will decide whether or not to launch a fully-fledged investigation into the matter."
Of the three witnesses, two had already been interviewed, Segalwe said.
The probe follows the landing of an aircraft, carrying 270 guests to a Gupta family wedding, at the Waterkloof Air Force Base in April.
The landing ignited widespread criticism. The DA and ANC called for a probe, while Cosatu called it "an absolute insult".
The Gupta family, which owns the New Age newspaper and Sahara Computers, were expected to celebrate the wedding of Vega Gupta (23) to Indian-born Aakash Jahajgarhia at Sun City between May 1 and 4.
The wedding guests were flown to the base and escorted from there by blue-light vehicles to Sun City in North West. The police did not provide the escort.
A private security company, which fitted blue lights illegally to vehicles with false number plates, was involved. South African Police Service and metro police officers in the security escort were later arrested.
Authorisation
Gupta family spokesperson Haranath Ghosh said at the time that the authorities granted permission to land at the base to the Indian High Commission, and not the family.
A ministerial report into the Waterkloof Air Force Base landing found that an initial attempt by the Gupta family to organise a special landing at OR Tambo International Airport was turned down.
The Guptas then approached the Indian High Commission, which re-designated the wedding entourage as an official delegation to secure a landing at the Waterkloof base.
The international relations department did not clear this and the commission dealt directly with the air force command post to obtain flight clearance.
"Name-dropping" was identified as the main cause behind the landing.
Chief of state protocol Bruce Koloane was suspended during a probe. A further five senior government officials and military personnel were suspended.
A government investigation exonerated President Jacob Zuma and his ministers, and found that the landing was the result of "collusion by officials".
Zuma was said to have been so infuriated by the embarrassment caused by the security breach that, on the same day, he ordered Defence Minister Nosiviwe Mapisa-Nqakula back from a meeting with her counterparts in Addis Ababa, Ethiopia. – Additional reporting by Sapa