It isn't exactly a looker, it is coated in foul-smelling slime and attracts flies.

But when Dr John Alban spotted this fungi, there was an instant attraction - for it turned out to be an Australian invader never seen before on these shores.

The species, spotted in Hethersett, is Australian basket fungi (Ileodictyon gracile).

Dr Alban, Norfolk's former county archivist, said he was out in Hethersett when he saw what he thought was 'discarded plastic packaging'.

He said: 'I realised that it was soft and might be something more natural. I then saw more of the structures emerging from gelatinous 'eggs' in the ground.'

He said his searches on the internet led him to suspect that they might be basket fungi so he contacted the Norfolk Biodiversity Information Service, the county's Biological Record Centre, at County Hall.

They passed the enquiry on to Tony Leech, chairman of the Norfolk and Norwich Naturalists' Society, who initially thought that they were specimens of the New Zealand basket fungus which had been found previously in just two places in Britain.

Careful examination revealed, however, that they were actually Australian basket fungi, never before recorded in this country. This has been confirmed by mycologists at the Royal Botanic Gardens, Kew.

Like the stinkhorn fungus, commonly found in British woods, basket fungi emerge coated in foul-smelling slime that attracts flies. The slime contains the fungus's spores which are dispersed by the flies to new places.

Mr Leech said: 'Basket fungi feed on organic material in soil and are quite harmless – but how they got from Australia to Norfolk is a real mystery.'

Dr Alban said: 'I was amazed by these intriguing structures, which resembled small footballs with the panels missing, and had almost an alien feel about them.

'I had never seen or imagined anything quite like them and not for one moment did I think that they had never previously been recorded in the UK. It's incredible that they should have arrived in Hethersett from the other side of the world – another first for Norfolk.'