Two New Zealand tourists will be blacklisted by Thailand following a shocking attack on a traffic police officer in Phuket.

Deputy police chief Pol Gen Surachate Hakparn said on Monday the immigration police chief in Phuket had been instructed to ban Oscar Day, 36, and Hamish Day, 34, after the court case against them. The two will not be allowed to come back to Thailand again.

The brothers entered Thailand on March 11 and were granted permission to stay in the kingdom until April 9. Visitors from New Zealand can come to Thailand without a visa for 30 days.

They were charged with robbery, obstruction of police on duty, physical attack against a policeman, driving without a licence and bribery.

The serious charges were imposed against Oscar and Hamish Day after they attacked and injured Pol Sen Sgt Maj Somsak Noo-iad of Chalong Station on Saturday. They were ordered to pull their motorcycles over as they were riding fast and failed to stay in the left lane. Instead of stopping their vehicles, they accelerated away. The traffic policeman chased them and when he caught up with the two, they wrestled him to the ground. They managed to take his gun which went off, but no-one was injured.

Police will oppose a possible bail request from their lawyers because they could jump bail and have no permanent address in Thailand.

Their parents are millionaire business and property owners named Laurence and Katrina Day, according to the New Zealand Herald.

"It's very, very concerning," The Herald on Monday quoted the father as saying. "The family is distraught. We're praying for a good outcome."