If at any time it shall be found that the person or entity to whom a contract has been awarded, or any agent thereof, colluded with any party for the purpose of procuring the contract or preventing the award of the contract to another, the contract shall be null and void and the City shall advertise for new bids thereon; provided, however, that in the case of public works or improvements, the Council may provide for the work to be performed by the City under the direction of the City Manager.