Landline hacked to make 111 calls 

A teenage hacker has discovered a way to use Telecom customers' private phone numbers to make prank 111 calls.

Telecom admits it is the first security breach of its kind, and the company is taking it very seriously.

"Over the Easter break I was standing in the kitchen making a coffee with a friend and got a call from police comms asking if we were okay," hacking victim Martin Pope says.

Pope had to prove he wasn't making the calls, which was hard to do when they all came back to his landline, he says.

"It was the endless head banging against the wall trying to get someone to listen," he says.

"There's actually a figure from Telecom of 425 times, which equates to just over $2,200 worth."

Telecom finally credited Pope back the money after several days.

The company believes Pope was the only customer stung by the hacker and say they have now closed the loophole that allowed it.

"There was a security breach over Easter.  It was identified quickly and it related to false triple one calls, no other calling was affected," spokesperson Phil Love says.

"We've taken steps to ensure that this problem does not happen again and we'd like to reassure customers about that," he says.

Telecom says they have referred the matter to the police who will be working with Telecom's fraud unit to keep tabs on the hacker.