They can, but not right away. To be able to require or demand this information or documentation, Labor would need to start a legal action against your employer. They can ask for the information voluntarily before that, and your employer may choose to provide it, but it takes a legal action to compel.Labor may start a legal action if they believe that you are being underpaid (e.g. no overtime, when you should get it) and the employer does not voluntarily prove to them that you are being paid correctly. If you contact Labor, provide as much information as you can about the hours you have been working.