A Niagara-on-the-Lake Hydro manager who was fired after stealing more than $250,000 is continuing to repay the money, the utility's CEO says.

So far, 77 per cent of the money has been recovered, NOTL Hydro president Tim Curtis told The Lake Report Tuesday.

The Niagara Regional Police said its criminal investigation into the fraud is proceeding but no charges have been laid.

On the advice of lawyers retained by the utility, Curtis said he could not release the name or personal details of the former employee, who was a senior manager.

The scheme involved phony invoices issued and paid over an 18-month period, he said.

A staff member in NOTL Hydro's finance department discovered the fraud while processing a payment.

In the wake of the discovery, hydro has been examining its internal procedures. Curtis said no evidence of any other fraud has been found