In a society that has no written language, this art is part history, part map, part biography and part illustration in the western sense. 'Australian Aboriginal art started being taken seriously by collectors' and the art world in the 1990s,' says Sotheby's director of Aboriginal art, Tim Klingender. 'Before this, it was the rare collector who purchased Aboriginal art or souvenir buyers who visited the more remote areas.

'This year's sale represented both the largest and most valuable collection of Australian indigenous art assembled for auction, and included an extraordinarily diverse selection of significant art and artefacts. We recorded excellent results, with strong bidding from the Americas, Asia, Europe and throughout Australia. About 50 per cent of sales this year went to overseas bidders.

'Buyers are showing growing interest in the more contemporary works as showcased at this auction.'

The auction also included rare paintings from the Kimberley region of Wanjina, by artists such as Charlie Numbelmoore, Alec Mingelmanganu and Wattie Karrawara.

Mingelmanganu's haunting Wanjina (1980) is the first painting to be offered by the artist since Sotheby's achieved a new auction record of A$244,500 (against a pre-sale estimate A$70,000- A$100,000) for a related work at last year's sale.

Among the paintings included by well-known Aboriginal artist Rover Thomas was a major work commissioned by Mary Macha Massacre Site -Old Texas Downs (1991), which was sold with a CD recording of Rover describing the meaning of the iconography depicted; Buragu (Lake Gregory) (1988) and Yillimbiddi Country (1988), both of which were featured in the artist's first solo exhibition in Sydney.

He came to prominence in the late 1980s when his reputation and commercial exposure grew. In 1990 he represented Australia at the Venice Biennale and the same year was awarded the John McCaughey prize for the best picture hung that year in the Gallery of New South Wales.

In 1994 he was involved in a landmark retrospective 'Roads Cross: The Painting of Rover Thomas', mounted by the National Gallery of Australia.

All these schools were represented at the Sotheby's sale. The most extraordinary painting was an enormous western desert work, Ngurrara Canvas No. 1. About seven metres wide by nine deep, it was painted in 1996 by 19 men and women working on a canvas in a remote part of Western Australia.

This breathtaking work realised an auction price of A$213,000 and was sold to a Perth businessman.

Paintings have been used in indigenous land claims since the early 60s, when the Yolngu of Arnhem Land petitioned the federal government against bauxite mining in their area. They were unsuccessful.

Other highlights of the auction were works by Emily Kame Kngwarreye, an artist Klingender describes as 'the most famous Australian contemporary female painter, indigenous or non-indigenous'.

With asking prices for her work increasing twentyfold over the past five years, her painting Untitled (Spring Collaboration) (1991) sold for A$509,300 - a new record for an artist heralded as the first superstar of contemporary Aboriginal painting.

Born at Utopia Station, north of Alice Springs, Kngwarreye's work has received wide acclaim since she painted her first work A Summer Project (1988-89).

She became the most famous painter of the Utopia art movement and one of the nation's best-known desert painters. Her works hang in the National Gallery of Victoria and are included in gallery collections in Dusseldorf, London and other European cities.

She died in Alice Springs in 1996 but left a legacy that has greatly impacted on the art world.

'Aboriginal art has a broad international appeal and is Australia's first really international art,' says Klingender.

'I believe this interest will continue and that ultimately Aboriginal art think it will become more valuable than non-indigenous Australian art.'