VANDALS poured floor cleaner, liquid soap and floor polish stripper into a water tank at a Camborne primary school, polluting the supply to its toilets and taps.

Police have launched an investigation following the incident at Rosemellin School, in Higher Rosewarne, on January 11 after someone poured the chemicals into a tank that feed the toilets and hand washing taps. The drinking fountains are fed from another system.

Fortunately, all of the products, which were taken from the school itself, were non-toxic. But they circulated in the school's hand taps and lavatories for the whole of the following Monday until the mixture of chemicals solidified and blocked the system.

Headteacher Ian Bruce said: "We have our own built-in system for drinking water and all the children here know to take their water from those places, but the people that did this didn't know that.

"They were pouring something into our water which they knew could cause harm. If they were big enough and strong enough to get in they were old enough to know what they were doing."

Mr Bruce said that in his 15 years of running the school, he has never seen anything like this before.

The school was first alerted to the break-in when the alarms went off at 3.30pm on the Sunday afternoon.

Deputy head Gordon Fenn and a security guard investigated and found a ceiling tile and strip light lying in a corridor.

Mr Fenn said he found it strange to find a strip light, as there were none in that part of the school, saying that he believed the offenders had used it to test whether the alarm was on.

There had been a power cut earlier that day, but the schools alarm system has its own backup supply.

It was not until various toilets stop flushing and some of the taps stopped running that contractors were called in and the "gunk" found blocking the system.

Investigations led to the discovery that the shed had been broken into and the school caretaker noticed that the cleaning products were missing.

Contractors had to completely flush out the water system before the next day's schooling.

Nearly 300 four to 11-year-olds attend Rosemellin School from the north Camborne area.

Investigating officer, Neighbourhood Beat Manager Marc Sayers said it was a "very unusual and potentially dangerous incident."

He has urged anyone who knows anything about the incident or saw anything unusual to telephone 08452 777444 quoting crime reference number AC 04180 or to call Crimestoppers anonymously on 0800 555111.