"The Chinese government has strict regulations on the reporting of epidemics and their disclosure," said Li Jinxiang, deputy director of the Agriculture Ministrys veterinary bureau.
"China's Ministry of Agriculture is a responsible entity and always provides timely disclosures when it has information on epidemics."
Vice Minister Gao Hongbin told reporters that the latest official number of pigs that had been infected with blue-ear pig disease had risen to around 290,000. This compares with 257,000 as of late August, 68,000 of those dying.
But experts quoted in the Western media have expressed doubts about China's official figures, suspecting the government is trying to keep a lid on a more serious crisis.
Li said China had been reporting outbreaks of the disease and had provided sequencing data of the virus to the World Organisation for Animal Health and the Food and Agriculture Organisation since epidemics were found last year.
He rejected Western media reports that China had refused to share virus samples with international organisations and other countries, arguing it had never received requests from them.
"To this day, the Ministry of Agriculture has not received request from any international organisations and other countries' laboratories for samples and viruses," Li said.
"Countries all over the world have very strict regulations on the import of viruses and samples."
Li also denied that a similar virus detected in neighbouring Vietnam and Myanmar had come from China, instead arguing that the blue-ear disease found in China displays similarity with the virus that originated from the United States in the 1980s.
"This demonstrates that China is also a victim and the (reported) spread of the disease to Vietnam and Myanmar is groundless," he said.
Last month, China's chief vet Jia Youling said some local authorities may have covered up the outbreaks but the problem was not as bad as reported by some media.
Jia said then more than 100 million of the country's 500 million pigs had been inoculated with an effective vaccine, which had been distributed to the regions most seriously hit.
He said the spread of the disease was now under "preliminary control."
No one at the Food and Agriculture Organisation's Beijing office was immediately available for comment on Monday.
The highly pathogenic blue-ear pig disease, or porcine reproductive and respiratory syndrome, is characterised by reproductive failure, death in young pigs and mild respiratory disease in pigs of all ages. It was first reported in the United States in 1987.
The spread of the disease has emerged as a major health concern for China and has been blamed for contributing to a sharp spike in prices of pork, a staple of the Chinese diet.