Badger groups and farming unions have clashed over preliminary results of a survey of bovine TB in badgers in Wales.

Tests on 459 found-dead badgers showed 55, or about 12%, were TB positive. The incidence varied in different areas, with up to 28% of positive results in Monmouthshire, a known hotspot for the disease.

"The results not only vindicate NFU Cymru's long held contention that TB is present in wildlife, but show that the disease is there at epidemic levels," said union president Dai Davies.

"Some 20,000 cattle have been pre-movement tested in Wales since May, with TB detected at the rate of 0.5%. Compare this to the rate of TB in badgers and it is obvious that action has to be taken to tackle diseased wildlife."

But Mr Davies complained about the anticipated four-month delay in publishing comparisons between the strains found in the two species.

The union was concerned that this might mean there would be no decision on the removal of diseased wildlife until after the Welsh Assembly election in May 2007.

The Farmers Union of Wales claimed it was no coincidence that the highest incidence was where TB in cattle was most common.

Evan Thomas, the FUW's TB spokesman, rejected the Badger Trust's interpretation that the survey revealed that 88% of badgers were not infected. "Imagine if one in nine of our children was infected with TB, it would be the worst epidemic in centuries."

A Badger Trust statement said: "The study shows that TB infected badgers are not found in areas where there are few or no cattle. This strongly suggests that the disease is not readily transmitted from badger to badger, and that badgers acquire it from cattle more readily than vice versa."