A sexually suggestive Venus figurine with oversized breasts and thighs dates back at least 35,000 years and shows ancient humans had sex on their minds, researchers said on Wednesday.

The 60-millimetre-long figurine may be the oldest piece of its kind yet discovered and suggests Palaeolithic art was far more complex than many had thought, Nicholas Conard of Tubingen University in Germany wrote in the journal Nature.

Radiocarbon dating indicates the figure excavated from an archaeological dig in southern Germany, near the Danube valley, was at least 35,000 years old, the researchers said.

"The discovery predates the well-known Venuses from the Gravettian culture by at least 5,000 years and radically changes our views of the context and meaning of the earliest Palaeolithic art," Conard wrote.

"Before this discovery ... female imagery was entirely unknown."

The figurine's enlarged breasts, bloated belly and thighs also make clear that sexual symbolism was alive and well tens of thousand of years ago, Paul Mellars of the University of Cambridge, wrote in a commentary.

"The feature of the newly discovered figure that will undoubtedly command most attention is its explicitly, almost aggressively, sexual nature, focused on the sexual characteristics of the female form," he wrote.

"Whichever way one views these representations, it is clear that the sexually symbolic dimension in European (and indeed worldwide) art has a long ancestry in the evolution of our species."