Local health authorities Tuesday admitted waiting for five months before announcing that secret recalls had been ordered for camellia oil by Jinhao, a well-known edible oil maker based in central China's Hunan Province, after the oil had been found to have contained excessive carcinogens.

An official with the provincial bureau of quality and technical supervision confirmed, on the condition of anonymity, that in March the bureau found excessive amounts of harmful elements, known as benzo(a)pyrene (BaP), in a sample of Jinhao camellia oil.

Benzo(a)pyrene is highly carcinogenic and will accumulate within human body, causing long-term health problems, according to health experts.

The official also said that the high level of benzo(a)pyrene remnant was resultant from the processing of the oil, which had been resolved by updating equipment.

But the official did not explain why the bureau only demanded Jinhao call back the oil, but did not publicize the result of the testing in March.

The Century Weekly, a Chinese magazine, reported Monday that Jinhao twice recalled the problematic oil without informing consumers or the media.

The benzo(a)pyrene level in the recalled oil, according to the report, was 60 micrograms per kg, five times higher than the national limits.

Jinhao, however, refused to publicly release information about the recalled batch or the quantity of products that had been recalled, the magazine said.

Public opinion boiled over soon after the report, with angry netizens decrying the cover-up and others worrying about camellia oil they had consumed.

"I bought the camellia oil as a luxury, now I have to discard it like trash. They didn't even tell me whether it is in the recalled batch or not," said a netizen "tittle-tattle".

A bottle of 5L Jinhao camellia oil sells for about 330 yuan (about about 49 U.S. dollars), roughly 4 times the price of normal peanut oil and indeed an expensive item for average Chinese families.

Wu Jingming, professor from China University of Political Science and Law, commented that local authorities reacted quickly to urge the recall of the problematic oil, but blundered in trying to hide the truth from the public.

Facing the online uproar, the oil maker, Jinhao, declined any comment, but said the oil currently being sold has been certified as being safe by local health officials.

As for the recalled oil, the only comment from a spokesman for Jinhao has been that the company would release information "in the days to come".

Camellia oil, acclaimed for its high nutritional value, has gained popularity in many regions of China. Hunan Province provides nearly half of all camellia oil sold in China, with Jinhao being one of the leading camellia oil producers.