Fumes from a septic tank may have caused the deaths of a father and his two sons in a farming accident in Co Down last night.

The victims have been named as 22-year-old Nevin Spence, who played rugby for Ulster, his 30-year-old brother Graham and their 52-year-old father Noel.

A daughter, Emma, was rescued at the scene and is being treated at Belfast's Royal Victoria Hospital.

Emergency crews went to the family farm in Drumlough Road outside Hillsborough in Co Down shortly after 6pm yesterday following reports that four people had fallen into the slurry pit.

According to John McPoland of the Northern Ireland Ambulance service, the slurry tank where the accident occurred was not much more than 1.2m deep.

Earlier, Northern Ireland Health Minister Edwin Poots described the accident as a terrible tragedy.

Mr Poots, who lives in the area, said the family involved were highly respected and known as good neighbours.

Rugby players and fans have also been paying tribute to Nevin on social media, while Director of Ulster Rugby David Humphreys described the news as devastating.

Chief Executive Shane Logan said they had received messages of condolence from many quarters, including the GAA.