From the air, the full extent of this ugly and dangerous blight on Norfolk's landscape becomes even more apparent.The dark mountains of 600,000 tyres at Tattersett Business Park continue to dwarf neighbouring vans and buildings after more than 10 years of ownership wrangles have frustrated efforts to clear the site.

From the air, the full extent of this ugly and dangerous blight on Norfolk's landscape becomes even more apparent.

The dark mountains of 600,000 tyres at Tattersett Business Park continue to dwarf neighbouring vans and buildings after more than 10 years of ownership wrangles have frustrated efforts to clear the site.

But despite assurances from environmental officers about the site's security, a county councillor this week said he is convinced the eyesore is still growing.

David Callaby, a member of Norfolk's Fire and Community Protection Review Panel, said witnesses had reported seeing more tyres being dumped at land adjacent to the business park.

And he said during his own inspections he had found tyres which were not degraded and covered in moss like the ones which had been lying there for a decade.

Environment Agency (EA) officials said the site was routinely visited and monitored by 24-hour security - but they had received no new reports of illegal dumping to investigate.

But Mr Callaby said: 'It seems like people are still dumping lorry-loads of tyres at that site. I was approached by a man who said he saw two cattle trucks with men unloading about 150 tyres in the early hours of the morning.

'When I have been on the site before I was not challenged and I found tyres which were manufactured in 2001 and 2002, which could not have been there very long.

'It is still growing - and how can the site be secure if it is not fenced on all four sides? It is a disgrace. It is an environmental hazard and at the end of the day the EA should be making sure these tyres are safe.'

About 300,000 tyres, a third of the original total, were removed by the EA in 2004 following a campaign led by North Norfolk MP Norman Lamb, who last month described the tyre mountain as an 'environmental time-bomb'.

An EA spokesman said: 'We have had nothing reported to us at all and without that we cannot investigate it.

'We do check the site periodically and there are 24-hour security people on the business park. If there is some evidence that people are driving in and dumping, then we would appreciate a call to our hotline. But it is not down to us to stop it, it is down to the landowner.'

The Tattersett tyre mountain became the property of French bank Soci�t� G�n�rale (SG) after the previous owner, Highstar Properties, was investigated by the Serious Fraud Office.

Since then, several business consortiums had shown an interest in the site, but a new buyer has not yet been found.

The EA spokesman said: 'We continue to work with the landowners to find a buyer who can take responsibility for the tyres.'

The EA hotline to report illegal tyre-dumping is 0800 807060.