Police in West Auckland say it may take some time for a young couple to recall details of an assault that left both horrifically injured.
They say the pair left their home in the suburb of Massey on Saturday night, and were found near Starling Park in Swanson on Sunday morning.
A couple walking their dog found the 19-year-old man in the park. His 17-year-old partner was found on the doorstep of a nearby house a short time later.
They have now been moved out of Auckland Hospital's intensive care unit and are in a critical, but stable condition.
Detective Sergeant Roger Small of Waitakere CIB says the police have been able to extract little information from them.
"They're are still heavily sedated, and obviously difficult as a result of the injuries being able to communicate and both of them, given they've suffered head traumas, have suffered significant memory loss."
He says it will be some days before investigators can determine what happened.
