"It is clear that he will be under constant supervision during transit and during the funeral,'' Justice Fogarty said.
Watson would be taken to the chapel before the funeral and discretely transitioned from the prison van to the chapel, in a way which would mean "he would only be in the public gaze for a few seconds, if at all''.
"Mr Watson wants to speak at the funeral with his brother and sister, and read a poem,'' the decision said.
Conditions included that he would remain under the supervision of two escorting officers, and that he would not converse with the public other than family members.
About 100 mourners turned at Westpark Chapel in Burnside this morning to farewell Bev Watson, who died on Friday after suffering a series of strokes. She also had leukaemia.
Reporters were not welcome and were escorted away by the funeral directors.
Watson's father, Chris - who has always insisted his son is innocent - said earlier that the family wanted the 42-year-old at the service.
His son had been allowed out several times to see his mother in the "couple of months'' she was in hospital.
Watson was convicted of murdering Ben Smart and his friend Olivia Hope in the Marlborough Sounds 15 years ago. Their bodies have never been recovered.