The police helicopter and checkpoints are being used in Marokopa in the search for Tom Phillips and his three children.

Police announced an $80,000 reward yesterday - and say they've had an increase in emails, calls and visits since.

Waikato Herald reporter Maryana Garcia says police are stopping cars going in and out of the town and the chopper has been up all day.

"The chopper's been flying over the Marokopa area, it came through this morning and it did a loop around that coastal area."

LISTEN ABOVE

• Marokopa fugitive dad Tom Phillips: Police reveal 12 more sightings
• Authorities suspect people assisting missing Marokopa man
• Police checkpoints set up around Marokopa as Tom Phillips search intensifies
• Police contacted with claims of information on missing family after reward issued
• 'Not the actions of a good father' - Police say missing Marokopa man armed, still a risk to the community
• Still armed and dangerous: Tom Phillips hiding in or near Marokopa, cops say