Detectives uncovered a plot to hold the biggest illegal rave ever staged in Sussex.

More than 4,000 revellers were expected at the party, which would have blasted out dance music at a volume equivalent to 25 jet engines.

But the organisers were ambushed by a team of police officers on the South Downs near Steyning just before the event was due to start.

When police arrived at Steyning Bowl - a hollow area of farmland - on Saturday night they found four stages, lighting and six sound systems being set up.

Thirty vehicles, including ten lorries used to transport equipment from as far afield as Cambridgeshire, North Hampshire and the Midlands, were parked nearby.

The police investigation began on Saturday afternoon when they received a tip-off that a very large rave was to be held "somewhere in West Sussex".

Patrols were put on alert and shortly before 11pm a police officer on the way to work spotted a convoy of lorries making its way along Bostal Road between Lancing and Steyning.

The police helicopter was used to search the Downs and the site of the planned rave spotted.

The organisers were ordered to pack up and leave or face being arrested and having their equipment confiscated. Hundreds of ravers who had started arriving for the event were turned away by police and by 3.40am on Sunday everyone had gone.

Inspector in charge Marcus Potter said: "This was going to be a huge event which would have caused a significant disturbance to the residents of Steyning and the surrounding areas.

"The sound equipment these organisers had set up would have produced the noise equivalent of 25 jet engines and they had been planning to play night and day until Monday afternoon.

"Fortunately the quick police intervention stopped the event from getting under way."

A rave at Kithurst Hill, Storrington, on April 22 led to more than 200 complaints from people in West Chiltington, Storrington and Steyning and other householders up to nine miles away.

A subsequent investigation led to the organisers being identified and arrested for causing a public nuisance and equipment worth thousands of pounds was confiscated.

If convicted of causing a public nuisance, organisers can face unlimited fines and imprisonment.

Police can use powers under the Criminal Justice and Public Order Act to order organisers to leave.

Horsham District councillor George Cockman, who lives in Steyning, said the disruption caused would have been enormous.

He said: "That area acts like an ampitheatre and the sound would have spread for miles.

"Apart from the all the noise, there would also probably have been a whole lot of mess left behind.

"Animals nearby would have been badly affected.

"We have not had a rave like this in this area for as long as I can remember and it would have been awful. I am relieved and delighted the organisers were stopped in time by the police."

Last August the Argus revealed how up to 500 people went to an illegal rave on land near Coombes Farm, Lancing, leading to concerns about the effect on livestock.

Angry farmers Jenny and Trevor Passmore were infuriated after being told there was little police could do because the events were being held on private land.