UP to 11% of petrol at fuel stations in Poland is of poor quality and could be damaging engines, experts have warned, although the problem has improved significantly in recent years.

In 2003, 30% of petrol was of improper quality at the beginning of the year and 22% at the end, an international meeting heard.

Fuel quality checks were carried out in about 1,700 petrol stations between May and October this year.

As a result, there were 171 cases where sites were suspected of selling fuel of poor quality, although only a few have so far been prosecuted, with fines of less than E150.