Two men who were attacked by a man with a weapon in Upper Hutt last night - leaving one with life-threatening injuries - had called police before the assault to say they were being filmed.
Police are seeking assistance from the public following the serious assault.
In a statement, police said two men were walking along Fergusson Drive near Caltex Rimutaka at about 8.30pm when they were approached by a man and seriously assaulted with a weapon.
One man was critically injured and was transported to hospital for emergency surgery.
He remains in a critical condition with life threatening injuries.
The other man received moderate injuries and was treated at hospital before being discharged.
Police said the same victims had contacted them at 7.50pm to report a woman who was following them, filming and taking pictures of them.
"We are working to establish whether these two incidents are linked," Detective Senior Sergeant Todd said.
Police have asked the woman who was filming the victims prior to the assault to come forward.
Anyone who was at the Caltex Rimutaka Fergusson Drive area between 7.40pm and 8.40pm have been asked to contact police.
Anyone who knows who the woman is also asked to contact police.