OXFORD City Council still does not know what chemical was used to dye Hinksey Pool purple.

The pool, in Hinskey Park, off the Abingdon Road, has been closed since Saturday, and Thames Water has been carrying out microbiological tests on a sample of the water.

The council will not know if it is safe to drain the 350,000 gallons until the tests are complete.

Even if it is suitable to go into the sewage system, swimmers will then have another wait of around four days to refill and reheat the pool.

A council spokesman said investigators expected the results of the tests to be in today or tomorrow- meaning the pool is likely to remain shut over the weekend.

Council deputy leader David Rundle said: "We realise how frustrating it is for users of the pool, despite the bad weather.

"We are hoping for good weather and a swift return of the service but we are always going to put safety before rushing to reopen."

Hinksey Pool would normally generate about £2,000 for the city council on a hot day, but the Met Office has predicted clouds and showers over the coming weekend, meaning visitors would have been down from a peak of 1,000 customers.