Police in Gauteng recovered a huge cache of arms and ammunition at a building in Randburg on Monday after receiving a tip-off from a contractor busy with alterations.

Sixty homemade hand grenades‚ seven AK-47 assault rifles‚ 16 pistols‚ 11 revolvers and hundreds of rounds of ammunition were found after several police units descended on the scene.

"We understand that the building has a new owner so when the contract workers were busy renovating it‚ they found a bag that looked suspicious and they called the police‚" police spokesperson Captain Mavela Masondo told The Times.

"We then came and summoned our Bomb Disposal Unit as well as our Dog Unit. When we opened the bag‚ there were indeed explosives and we then went on to search the building."

In one of the rooms in the basement‚ police found AK-47s‚ revolvers‚ R1s‚ pistols‚ bombs and "quite a lot of ammunition".

The police said nobody had been arrested in connection with the cache but they were investigating who the building used to belong to.

The Times understand that it used to be a block of flats as well as a hardware store.

Earlier this year‚ The Times reported that the police had been mum for over a year regarding the theft of 20‚000 rounds of ammunition from a Pretoria police station. No arrests have been made and no disciplinary action has been taken against those implicated in an internal police investigation.

It is unclear whether Monday's find is connected to that case.