A freak thunderstorm which swept over Sussex on Friday sparked a rare weather phenomenon in the Channel.

Chris Alcott, who lives in The Drive, Shoreham, spotted a waterspout off the town at 6.40pm.

He said: "I watched it for about two minutes and it was definitely a waterspout.

"It was a dark finger of cloud pointing down from the base of the cloud layer.

"It was a classic tornado spiral, I have never seen anything like it before."

Ray Kemp, spokesman for the Environment Agency, said Sussex had had a very lucky escape as torrential rain battered the county.

He said river levels weren't too high, so they were able to take most of the excess water, although there were reports of flooding in the Midhurst area.

Meanwhile, the, agency is trying to trace the source of an oil spill which could have caused a major environmental disaster.

Heavy rain broke up 20,000 litres of oil-contaminated water which was pouring into the River Arun, near Ford, near a site of special scientific interest containing rare forms of wildlife.

Seabirds were contaminated by the oil, believed to have come from a local industrial estate. Mr Kemp said: "We haven't managed to trace the source yet, but our investigations will continue until we do.

"It was a lucky escape and the torrential rain prevented a major disaster. The majority of the oil was washed out to seabirds affected."

Mr Kemp added: "It was also fortunate that the oil was not a heavy type, as we originally thought.

"We were worried a pipeline had broken, but we don't believe that was the case now.

"We had hoped to put a boom across the river to stop the oil travelling downstream, but we had to give up because of the torrential rain."