The South African Police Service (SAPS) was tight-lipped on Thursday about how robbers made off with cash from OR Tambo International Airport on Tuesday.

"All we can say is that there has been a security breach at the airport and we will beef up the security at the airport," acting National Police Commissioner Lieutenant General Khomotso Phahlane said.

He was speaking at media briefing at the GCIS offices in Pretoria on Thursday, following a multi-million rand cash heist, where it is alleged that armed men made off with R24 million. There has been no official confirmation of the figure.

A vehicle used during the daring heist was recovered in Pretoria. A highly placed source told News24 that the vehicle had been found on Tuesday night with several empty boxes which had held the cash. The source said senior Hawks investigators were probing a police connection in the heist by using a tracker system.

The source said the cash was stolen on Tuesday from a plane which was destined for the UK.

The currency of the stolen loot is unknown at this stage, but is believed to be a mixture of rands, euros and US dollars.

Phahlane said the police viewed the robbery in a serious light and were working around the clock to track down the suspects.

He said a multi-disciplinary team was investigating the matter.

"We have started a process where we are investigating and trying to identify the security shortcomings and to implement measures to prevent an incident of this nature from happening again," he said.

He said initially there was speculation that SAPS vehicles had been involved in the crime, but this was not true.

"A vehicle which was found abandoned in Mamelodi proved to be one with fake police markings. When the perpetrators are arrested we will not be surprised when we find out that they were bogus police officers."

Phahlane said all the equipment and uniforms that were used by the suspects would form part of the investigation.

Phahlane gave little detail about the cargo, saying it remained part of the investigation.

"If that was illegal cargo, it would have not been processed to the point at which it was. Cargo was legal," he said.

Phahlane assured South Africans that the airport was safe as it is a national key-point. He added that security would be beefed up.

"One incident cannot define the SAPS as an institution that is not doing well."