Can we retrieve hours that were deleted from a timesheet and identify who deleted them?

Yes, our Timesheet Audit Trail report shows what data was changed in each timesheet. It also includes a Modified By column, and shows the original and new value for each changed field, including the Hours field.

Related links

Using Replicon reports
Does Replicon record an audit trail of changes?
How do I correct my timesheet after I've submitted it?
How do I edit items before approving them?
Correcting an item