Department of Agriculture investigators have uncovered a new method being used by some farmers to interfere with the results of bovine TB tests.
Following an undercover investigation in west Cork a farmer may face charges relating to injecting his animals to infect them with the disease.
Department sources say that a substance not known to have been used before for this purpose was being used by the farmer and a file is being prepared for the DPP by gardai.
The farmer stood to benefit financially if his entire herd had to be destroyed because of bovine TB under the generous grants available from the Department.
The Department's Control Inquiry team is now looking at other herds in the area which may have failed the bovine TB test.
Earlier this week the Irish Veterinary Union said there was a huge increase in the incidence of bovine TB over the past year.
The IVU president, Mr Paschal Gibbons, said that 1998 saw 44,000 TB reactors removed from the national herd in what he called "a significant and inexplicable" increase on previous years.
He said his organisation would be taking the matter up with the Department of Agriculture and he called for the reintroduction of the mandatory testing of cattle before they are allowed to be moved from a farm for sale.
"The abolition of the pre-movement test has undoubtedly played a part in the increased incidence of TB and brucellosis in cattle in recent years," he said.
He said that the abolition of the pre-movement TB test in 1995 against veterinary advice and against the will of many farmers had contributed to the significant increase in TB in the last two years. Mr Gibbons also called for action in dealing with TB in the badger population.