Researchers believe a deadly rabbit disease could be to blame for killing East Anglia's wild hares, after discovering the virus has jumped across species.

A team led by the University of East Anglia has detected rabbit haemorrhagic disease virus type 2 (RHDV2) in brown hares in Essex and Dorset.

The disease is known to have infected European brown hares in Italy, Spain, France and Australia, but this is the first time it has been confirmed in hares in the UK.

The UEA joined forces with Norfolk, Suffolk and Essex Wildlife Trusts and the APHA (Animal and Plant Health Agency) to investigate reports of sick and dead hares found around Bungay, Diss and Thetford in September. Sightings then started arriving from across the UK.

Lead researcher Dr Diana Bell, from the university's School of Biological Sciences, said RHDV2 is just one possible cause of the deaths but, as cases have now been confirmed in other counties, the virus is likely to have spread to Norfolk and Suffolk.

She said: 'RHDV2 is one of several pathogens we are finding in dead hares and it is too early to say which is currently the primary cause of the hare die-off.

'It could be European brown hare syndrome, or RHDV2, or something else. Some have got lesions that look like myxomatosis, so we are still looking into that.

'But I think if RHDV2 has spread to these two remote locations, and it has spread on the continent, it is likely to happen across the country, unfortunately.'

Dr Bell said if the disease did spread across East Anglia, it was too early to say what the implications would be for the European brown hare species.

'That is what we have got to monitor now – to see if it is a one-off, or if the animals develop resistance,' she said. 'We are in uncharted waters. But this is one of several diseases we are investigating, and there will be more results soon.'

East Anglia is an important stronghold for brown hares, which have experienced a national decline of more than 80pc in the past 100 years, attributed to factors including the intensification of farming, which has limited their supply of food and habitat.

There is also no closed season for hares, which means that they can be shot legally at any time of the year, and illegal hare coursing is a rising rural concern.

• The research team is continuing to collect dead hares for autopsy. If you find a freshly dead hare, report it to Dr Bell by emailing d.bell@uea.ac.uk.