Police believe veteran journalist Derek Round had been in recent contact with the person who killed him in a horrific attack at his Whanganui home.
Mr Round, 77, was found dead in his Whanganui house on Thursday.
He suffered a number of violent blows to the head after being attacked in his living room.
Detective Senior Sergeant Dave Kirby said investigators believed the person who carried out the attack had been in contact with Mr Round in the days leading up to his death - either by phone, text or in person.
"Because of this we want to hear from anyone who had dealings with Derek in the week before he was violently attacked."
Mr Round's distinctive 1996 blue Jaguar XJ6 was spotted on Thursday morning in the suburb of Aramoho.
Mr Kirby said investigators believe the killer had driven the car to a property on Field Street, where a scene examination had been launched.
Police also believed clothing they had been searching for since Thursday was worn by the person who killed Mr Round, Mr Kirby said.
They wanted to find red long sleeved jersey or sweatshirt, a black leather sleeveless vest, dark coloured stonewashed jeans, dark fingerless gloves, and a pair of dark coloured sports shoes with white around the soles and coloured laces, he said.
He appealed anyone who had been in contact with Mr Round before his death to come forward to investigators, even if they did not think they had useful information.
"The pieces of this puzzle are slowly coming together and I remain very confident that, with the help of the public, we will get who was responsible for Derek's death"
During his career spanning more than five decades Mr Round held roles as an editor and was foreign correspondent. In 2010 he was made a member of the New Zealand Order of Merit for his services to journalism.
He also once worked as a spy and had links to the KGB.