The head of Calgary's flagship colon-cancer screening centre is blaming his frontline staff for allowing favoured patients to be pushed up two years in the queue.

Dr. Alaa Rostom told Alberta's queue-jumping inquiry the booking clerks don't have that authority and shouldn't have been doing it.

The clerks at the Forzani and MacPhail Centre have already testified they were directed by doctors, nurses, and supervisors to move patients up in line in 2010 and 2011.

While ordinary patients had to wait three years to be seen, the favoured patients were referred, examined and treated within months.

Many of those patients came from the exclusive Helios Wellness Centre, a private centre offering care to a select clientele.

The booking clerks also ordered that many of the favoured patients were to be seen only by Rostom or by two other doctors -- but Rostom says he doesn't know why that would have been done.