Officers continued their inquries in Kawhia yesterday and were back there today.
Mr Carpenter said they had received information and images from locals and people from Taranaki, Feilding and Whangamata who were visiting at the time of the attack.
"The images and information provided are assisting us greatly in building an accurate picture of what happened before, during and after the event as we work to build up a case that will have its eventual conclusion in court,'' Mr Carpenter said.
Mr Griffin, who is the sole charge officer in the coastal town, is recuperating with family after the incident at Kawhia wharf while trying to arrest a 19-year-old man on January 11.
Three people have appeared in Hamilton District Court on charges stemming from the attack.