Cao Qianjin's water purifier business was not doing well so he dreamed up an unconventional marketing plan to stir up business: he poured toxic pesticide into a reservoir in the hope that frightened locals would buy his products. Sixty-four people from Ruyang county in Henan province fell ill last Wednesday after drinking the poisoned tap water. Forty-two of them were admitted to hospital and 9,000 families were without water after the service had to be cut off, Xinhua reported. Cao, a 27-year-old who had been laid-off from a state-owned enterprise, set up a small shop in July to sell the purifiers. He ran the business with his wife, who had also been laid off. Sluggish sales meant they could barely scrape together a living. Cao told police that he came up with the idea to poison the water after reading a label on one of his purifiers that said the product could filter out pesticides and other toxins. He thought that if he poisoned the water the whole village would want to buy his products and his business would be saved. So Cao bought 6.6kg of pesticide and poured a small amount into the reservoir. Police arrested Cao after a four-day investigation. Local officials said the poison had not been fatal because it had been so heavily diluted. By yesterday all the victims had been released from hospital. The water service has now been resumed but locals are still concerned, saying the water carries a strong odour. The central government recently introduced tough sentences, including long prison terms and the death penalty, for people who use toxins for malicious attacks.