"This was a really dumb and stupid thing where they weren't thinking about the extra risks involved with driving through a tunnel," he said.
They were following closely behind each other and were stopped by a patrol car travelling to Lyttelton.
The police officer clocked the excessive speed on his radar, did a U-turn and followed the two drivers, who pulled over outside the tunnel.
They have both been suspended from driving for 28 days and have received a summons to appear in court on June 17 for excessive speed.
Police have the power to automatically suspend someone's licence for 28 days for several different reasons, including if you are caught travelling 40km/h or more over the speed limit.
Sgt Peoples said motorists travelling through the tunnel usually stuck to the speed limit.
If drivers were caught speeding, it was usually at about 70km/h.
Sgt Peoples called this instance extreme.
"Some people don't really appreciate the hazards in the tunnel," he said.
"It is relatively narrow. It often sees heavy traffic. There are areas where there can be water on the road from leakage, tunnel maintenance and cleaning and this can make the road quite greasy, being an extra hazard."
Sgt Peoples said crashing in the confines of a tunnel could be a major problem.
If there was a crash it magnified further problems that could occur, such as fire and accessibility for emergency services.
