IMO, Sydney does the check. The government doesn't give the power for every local office to check applicants' background, to avoid being misused if so many CIC officers could do it. With only one (Sydney), it's easier to control. Then when your file being transferred, it's already marked being given finger print or RQ. The local office just executes the order or give you a test and oath. But they can also give you problem if they find something fishy during your interview.