Ottawa's largest union says city Auditor General Alain Lalonde has wasted taxpayer money by not tendering contracts. ((CBC))

Ottawa's biggest union has accused the city's auditor general of wasting taxpayer money.

The Canadian Union of Public Employees (CUPE) Local 503 said Friday it has obtained documents through access to information requests that show Alain Lalonde, who has served as the city's auditor general since 2004, has put only a handful of contracts for work in his office up for public tender.

"If he's the public purse watchdog, I think he can do a hell of a lot better job than he's doing now," said CUPE spokesman Clarence Dungey.

"Just under 100 contracts were let out by his office, only eight of them went out to be tendered."

Dungey said Lalonde's office spent about $4 million on contracts to help audit departmental spending over the span of four years.

Lalonde told CBC News the majority of those contracts were small — around $50,000 — so it wouldn't make financial sense to put them up for tender.