A stomach bug which affected 140 people in the north-east of Scotland has been traced to a water treatment plant, it has emerged.

Solicitors acting for almost 60 of those who fell ill said that finding would help speed up compensation claims.

Scottish Water has since announced a �10m investment plan to ensure a similar outbreak of cryptosporidium, which can cause diarrhoea and stomach cramps, does not happen.

There are normally between 500 and 1,000 cases of cryptosporidium infection in Scotland each year.

Money is being invested in new equipment

People living in the Aberdeen area fell ill between January and March, and health officials found higher than normal levels of the cryptosporidium parasite in the water supply.

This prompted an investigation into the source of the outbreak.

Scottish Water found holes in the bottom of filter beds at one of its water treatment plants and this is thought to have contributed to the high levels of the bug found.

Ken Hutchison, of Scottish Water, said the faults have been corrected and the company would spend �10m to bring about further improvements.

But the company stopped short of fully accepting the problems at its plant led to the cryptosporidium outbreak.

The infection is uncomfortable for most healthy adults, but they rarely need to be admitted to hospital for treatment.

It can, however, lead to severe health problems for people with weakened immune systems.