Mr Johnston declined to comment yesterday on what Mr Keogh's injuries were or who the altercation was with, but he said it was not gang related.
"Police are investigating a dispute which occurred in the Fairburn area prior to this," he said.
"Our victim is a father-of-four and two of his children were witnesses to the events of [Saturday] night."
Kaitaia Police have a team of 17 staff working on the homicide inquiry following the man's death.
A number of child specialists are included in the police team, helping to provide support to the four children.
His children were aged between 3 and 13 - it was the two eldest who witnessed the altercation.
Mr Johnston said the priority was looking after the children and giving them all the support possible.
"They have suffered a great trauma," he said.
He said Child, Youth and Family had assisted by providing specialist interviewers and ongoing trauma counselling.
"We are doing everything we can to try and support these children. They have witnessed a very traumatic event and have lost a dearly loved relative. Police are working closely with CYF and Victim Support to provide whatever help we can to the family."
Police said the two men were known to each other.
Yesterday, police were still carrying out an examination of the roadside scene and a vehicle belonging to the victim, Mr Johnston said. They were also interviewing witnesses.
"We're still in the very early stages," he said.
Mr Keogh was rushed to hospital, about 15km away, by members of his family.
His body has since been transported to Auckland for a post mortem examination today, and his death has been referred to the coroner.
In 2013, the Fairburn community was shocked by the murders of Ivan and Carmen Maheno, killed by their nephew Edwin Harvey Maheno. He was sentenced to life imprisonment with a minimum non-parole period of 18 years.
