Gift packs of oolong tea sold at the National Palace Museum (NPM) were found to contain pesticide residues, according to test results publicized by the Taipei City Department of Health Monday. Two different pesticides - flufenoxuron and ethion - were found. Both are banned on tea plants in Taiwan, the city department reported. The department said people who have purchased the problematic products can return the merchandise and get a refund. The producer faces a fine for violating the act governing food sanitation, and has been ordered to destroy all the substandard tea products, department officials said. The city government conducted the safety check a few days ago on three different kinds of fermented Taiwanese tea products sold at the museum -- named Oolong Tea, Spring Four Season Tea, and Chin Hsuan Tea -- after a local tabloid weekly journal exposed the problem. City official Chiang Yu-mei, who is responsible for health affairs, stated that no pesticide residues were found on the other two products. The museum can put the products back on the selves for selling, she added. The city Department of Health report shows that the tested oolong tea was found to contain 0.12 ppm of flufenoxuron -- a pesticide that can cause cancer -- and 0.16 ppm of ethion, an insecticide that can damage the nervous system. The Taipei County-based trader 'iTea' was found to be the contaminated tea supplier, but NPM claimed that the tea it sold was produced from Nantou County, one of the major tea producing areas on the island. The Taipei City government said it has asked the relevant local authorities to take measures to punish the company and producers involved for violating the law. They will be subjected to a fine of between NT$60,000 (US$1,860) and NT$300,000. If they are found repeating the wrongdoing within a year, their business or factory licenses will then be withdrawn, it added. As most pesticides are water-soluble and sensitive to high heat, Chiang suggested tea drinkers use boiled water at the temperature of higher than 80 degrees Celsius to make tea and drain the first pot of tea. Meanwhile, NPM Deputy Director Feng Ming-chu announced at a press conference earlier in the day that the museum has withdrawn its contract with iTea, and that it has also asked the company to compensate for the losses. Feng apologized to the public for the problem, and pledged measures will be reinforced to screen the safety of all the products sold at the museum. Responding to Next Magazine's report on Nov. 11 saying all NPM tea products were contaminated, Feng said the museum has taken all tea products off the shelve soon after it was informed of the report, but the tests have proved only one product is problematic. 