Internal auditors are digging into another year's worth of financial records at the municipal depot in St. John's.

They are going back though a fourth year of invoices and purchase orders.

Since the investigation started in January, auditors have uncovered close to $100,000 in questionable spending over two years.

St. John's mayor Dennis O'Keefe said the auditors have since gone back through a third year of financial statements, and what they've found warrants even more work.

"The investigation is continuing, and at the end of it justice will take its course," declared O'Keefe.

He said a decision on whether police will be made after the city's review is completed.

A former senior city manager at the centre of the investigation has since retired.