The private information of more than half a million Albertans has been compromised after a laptop was stolen from Medicentres.

Alberta’s Health Minister Fred Horne says he wants to know why it took so long for the company to reveal the theft to him.

Horne was given a letter Tuesday detailing how a laptop was stolen from Medicentres Family Health Care Clinics in Edmonton.

Medicentres sent a letter to Horne to let him know that the laptop contained names, dates of birth, health card numbers, billing codes and diagnostic codes of 620,000 Albertans.

Medicentres' Chief Medical Officer of Health, Dr. Arif Bhimji says the company has placed ads in Thursday's newspapers to let people know about the situation.  He says the company apologizes for what has happened.

The laptop was stolen in September, 2013.   It belong to an IT consultant who was working with Medicentres and was using the data to run a new application.  Medicentres says from now on all information on laptops, including those brought in my consultants, will be encrypted.

Horne says he requested an official investigation under the Health Information Act.

Medicentres is encouraging patients who went to any of the Medicentres clinics in the province between May 2, 2011 and September 19, 2013 and have questions - to call  780-484-8741 OR email MEDICENTRES.

In a statement from Medicentres it says "(Medicentres) has no information suggesting that the personal information contained on the laptop was accessed or misused.  Affected patients are encouraged to review bank and credit card statements and report any unusual activity immediately to their financial institution. Affected patients can also visit the Privacy Commissioner’s website".