A pesticide whose use in Greece has been banned for years is believed to have caused the deaths of around 50 cows on a farm in the Axios River delta, according to veterinarians who inspected the dead animals. Authorities in Thessaloniki are seeking to determine who used the banned chemical and whether it was done with the intention of killing the cattle. «Everything seems to point to a willful act but this remains to be proven,» a local official said. The owner of the cows, who has another 150 animals on his farm, has lodged a legal complaint against all persons responsible. Meanwhile scientists are conducting tests on samples of local animal fodder and water to determine whether the chemicals might have entered the animals through the food chain. Last week a Thessaloniki prosecutor ordered an investigation into allegations that a large warehouse has been built in a protected area in the Axios River delta.