Despite preparations made ahead of the death of former president Nelson Mandela‚ South Africa’s military briefly “lost control” of its airspace as heads of state arrived to pay their respects at his memorial service‚ according to a US Defence Intelligence Agency memo.

This was revealed in a series of redacted intelligence documents made public by the Washington-based group Property of the People on Wednesday to mark the 100th anniversary of the birth of Nelson Mandela.

The cache of documents‚ dubbed “The Mandela Files”‚ was obtained after years of litigation and appears to show how US intelligence agencies monitored Mandela and events around the former statesman‚ even after his release from prison.

A Defence Intelligence Agency memo‚ circulated as an “information report” that had not been finally evaluated‚ dated December 2013‚ claimed that the South African Air Force had become “overloaded” and briefly “lost control” of their airspace over Waterkloof Air Force Base during the influx of heads of state who jetted in for his memorial service.

“The SA Air Force lost control of the airspace of the Waterkloof AFB on the morning of December 9 [2013] and had difficulties in managing the influx of Heads of State aircraft for the memorial service for Nelson Mandela‚” the memo said.

The SANDF however‚ has poured cold water on the claims.

"The management of the airspace and parking of aircraft at Air Force Base Waterkloof and other designated airfields was done according to a well-coordinated and executed plan during the funeral service of Mr Nelson Mandela‚" said Brigadier-General Mafi Mgobozi on Thursday. "There was no unauthorised parking‚" he added.

"The documents‚ which are apparently circulated‚ are not intelligence nor finally evaluated. They are treated as information‚" he added.

The memo reads: “Over 90 Heads of State arrived at Waterkloof AFB from December 8-9 2013 for leaders to attend the December 9 2013 memorial service for Nelson Mandela. Due to prior poor planning from the government on the preparation and execution of the events to honour Mr Mandela after his passing‚ the SAAF was not prepared to receive so many (heads of state) aircraft in a short time span.”

The memo said that two days ahead of the memorial service‚ the Air Force had notified all foreign embassies that their heads of state would be given clearance to land at Waterkloof on the day of the memorial service while all other aircraft not carrying heads of state were directed to land at Lanseria airport.

The notification stated that “all aircraft‚ regardless of being HOS (heads of state) or not‚ needed a landing clearance prior to landing”.

But come the morning of the memorial service‚ several aircraft entered the airspace around Waterkloof without clearance‚ said the memo.

“The aircraft disregarded host nation guidance and proceeded to land at [Waterkloof] without landing clearance. To not have to admit to allowing uncleared aircraft to land at the SAAF base‚ the South Africa Overflight office issued verbal landing clearance to [Waterkloof] as the uncleared aircraft touched down at Waterkloof.”