Mahy lives immediately behind the beachfront property next to the one at which the remains were found and can see the pedestrian access to the beach from his home.
"I saw two police cars arrive and a bather came running up to the [pedestrian] entrance and then pointed."
He was tired and went back to bed, but his wife, Pam Mahy, spoke to their neighbour about 7am.
Neither their neighbour nor police were able to say what was going on, but she saw forensics' officers in white boiler suits, as well as a police photographer.
It was a shocking moment when he realised what was going on, Fillmore said.
"I didn't know what was happening at first. I thought there must've been a burglary.
"There must've been 12 police officers out there, there was a hell of a lot."
The Herald asked police this morning if they had any information yet on the identity of the remains or how they came to be on the beach.
We also asked police for details on missing persons' cases being considered and whether they had been contacted today by any family or friends of missing people.
A police spokeswoman said it was too early to give answers to our questions.
"We have a team of investigators working on this and are working to identify the remains as soon as possible, however at this stage I have no indication how long this might take."