Jinhao camellia oil was pulled from the shelves at a supermarket in Beijing on Thursday, September 2, 2010. [Photo: Legal Evening News/CFP]

An edible oil maker in China's Hunan Province has issued a letter that details the information on its oil products that were found to contain excessive carcinogens.

The camellia oil in question involves nine batches, measuring 42.458 tons, produced by Jinhao from December 3, 2009 to March 17, 2010, the company said in the letter on its website Wednesday.

The Hunan provincial authority of quality and technical supervision confiscated 22.361 tons of the oil at the company's warehouse and recalled 11.152 tons, the letter said, but did not give specific dates.

The company itself made unspecified recalls of the oil products on March 20th and April 22nd respectively, yet it is believed an unknown amount of the products are still to be recalled from the market, according to the letter.

It lists the names, production dates and volumes of the camellia oil products, and the amount of the carcinogen contained, benzo(a)pyrene (BaP), in micrograms per kg.

One type of product dated December 3rd contains 40 micrograms of BaP per kg, although the national limit is equal or less than 10 micrograms per kg, the letter showed.

The company claimed the excessive amount of the carcinogen was generated due to its defective leaching technique during production, and camellia oil made with the technique only accounts for 1.08 percent of its production volume.

The company has since upgraded its technique, and product samples tested by quality authorities revealed no problems, it said.

The company admitted in the letter it did not make public the recalls and the batches of the products involved in a timely manner.