The Mayor's inner circle has approved a deeper probe into how a $20 million dollar lawsuit over the city's water treatment plant fell apart.

Three weeks ago councillors learned the claim was dropped after key deadlines were missed. A senior city lawyer was fired over the botched lawsuit.

READ MORE:

City lawyer fired over lawsuit flub: Winnipeg mayor

Mayor, councillors want deeper investigation into water treatment lawsuit dismissal

City seeking outside advice over water treatment plant lawsuit

Members of Executive Policy Committee called the mistake serious and catastrophic.

As a result EPC has asked the city CAO for a chronology of events that resulted in the failure and that the city auditor do a review of the legal services department.

Outside legal council will also investigate and determine if the city can recoup any of the losses through the Manitoba Law Society's liability claims fund.

A report is expected back in four months.