Southern Water has been fined £5,000 for allowing sewage to contaminate the upper reaches of the Beaulieu River at Lyndhurst for the second time in two years.

The company pleaded guilty at New Forest Magistrates' Court on Tuesday to allowing the sewage to seep from a corroded pipe at Lyndhurst. It also had to pay costs of £1,312.

A more extensive spillage of effluent into the river occurred from Lyndhurst Sewage Works in 2002 when Southern Water was fined £30,000.

Peter Bilbrough, for the Environment Agency, said that, on July 4th, 2003, Southern Water alerted it to the spill and officers from both organisations rapidly dealt with the incident.

Agency officers noted a foul smell and faeces floating in the river. Dead trout were also seen in the water.

Later, within 100 metres of the discharge, officers found that 40% of freshwater shrimps were dead. Ammonia at three to four times the dose fatal to fish was found in the water.

Downstream by 500 metres, the impact was much less significant.

Clifford Darton, for Southern Water, which owns and operates the sewage pipe network, said that in the 1970s, cast-iron pipes, which had a life of 60 to 70 years, were installed at Lyndhurst,

Investigations showed that pipes either side of the corroded length were in good order and he suggested that there must have been some compound in the soil to cause this corrosion which, because it was external, could not be detected by the company's inspection equipment.

Mr Darton claimed that the river quickly recovered from the pollution - but this was disputed by the Environment Agency.