CAUGHT: The alleged thief is taken away by police.

A builder and a painter whose tools were stolen in a daylight theft chanced upon the man who allegedly pilfered their drill and sander and detained him until police arrived.

The theft occurred yesterday morning at the Palmerston North Boys' High School College House dormitories, currently under refurbishment.

Boys' High property manager Tom Abbott said the contractors had put their tools down for morning tea when the man walked into the empty dorms.

FAITH SUTHERLAND/Fairfax NZ HELPING POLICE: Tom Abbott, left, identified the alleged offender on security footage and called the police while a painter and builder performed a citizen's arrest.

"I came back after morning tea and noticed some of the tools were missing," he said.

"So we looked for them, tracing our steps, thinking I might have left it somewhere, then one of the cleaners told another contractor her phone had been stolen."

Mr Abbott immediately looked through security footage held at the school and found an unidentified man "stroll in, pick up stuff and disappear".

"I printed off the clearest photo and took it to the local boarding establishment where a man identified the guy, so I made a report at the police station," he said. "But as we were returning to work we saw him across the street by the dairy."

The alleged offender was having an icecream.

While Mr Abbott rang police a painter and a builder from the school performed a citizen's arrest outside the Trenton Mini-Market on Featherston St, preventing the man from escaping.

"We did a U-turn, parked up and called the police," he said.

"It's a score for the good guys - for us it's satisfying because thievery spoils it for everyone, nothing good can be said about thieves."

Mr Abbott said he was hopeful the builder and painter would be able to get their tools back. The cleaner's cell phone was also going to be returned.

Constable Dominic Lamont said a very low-end burglary occurred yesterday and the man was caught by people who identified him.

He was arrested and will appear in court at a later date, he said.