South Africa's military faced questions Wednesday over how a rich Indian family close to President Jacob Zuma was able to use a restricted military base to fly in VIP guests for a lavish society wedding.

An Airbus chartered by the Gupta family landed at the Waterkloof air force base in Pretoria on Tuesday to ferry in about 200 people from India -- reportedly including Bollywood actors and foreign dignitaries.

Leading union confederation Cosatu and the ruling ANC said they were demanding answers from the South African National Defence Force over the alleged misuse of government resources.

"It is an absolute insult to the people of South Africa that private individuals can use a public facility for their social activities and that state officials should escort them," Cosatu spokesman Patrick Craven said in a statement.

He said Cosatu was seeking an urgent investigation into who authorised the airfield's use for a purely private function, warning of the possible risk to national security, and said those responsible should be disciplined.

The Gupta family, originally from India, is one of the richest in South Africa, with a range of businesses including Sahara Computers and the New Age newspaper which is considered the mouthpiece of the ANC.

The guests were being flown in for the celebrations kicking off Wednesday for the wedding of 23-year-old Vega Gupta in the resort of Sun City.

Media reports said Bollywood singers and actors were among the guests for the marriage of Vega, the niece of the three Gupta businessmen brothers, which is being described as the "wedding of the year".

Defence force spokesman Siphiwe Dlamini said that as far as he knew no permission had been granted for a private citizen to use the base.

But Gupta family spokesman Gary Naidoo said that the force had granted permission for the aircraft -- which was carrying "foreign ministers and other dignitaries" -- to land at Waterkloof.