A New South Wales Supreme Court jury has found a farmer guilty of murdering Office of Environment and Heritage officer Glendon “Glen” Turner.

The jury found 81-year-old NSW farmer Ian Turnbull guilty of murdering Mr Turner, 51, at his Croppa Creek property in the state’s north in July 2014.

The five-week trial heard Turnbull shot Mr Turner several times and chased him around a car for at least 22 minutes before fatally shooting him in the back in July 29, 2014.

Mr Turner had admitted taking his rifle and firing several shots at Mr Turner but pleaded not guilty to murder.

The attack followed years of tension and a legal battle with the environment department over allegations of illegal land-clearing on the Turnbull family’s properties.

Turnbull’s lawyers argued for a manslaughter verdict, saying the farmer snapped under the immense pressure of persistent legal action.

But the jury rejected that argument with Friday’s verdict.

A sentence hearing has been set for June 15.

– with other agencies