Copies are acceptable, but they have to be "certified" to the IRS's standards.
According to Supporting Documentation Requirements on page 3 of the Instructions for Form W-7,
You must submit original documents, or certified copies of these documents from the issuing agency, that support the information provided on Form W-7. A certified copy of a document is one that the original issuing agency provides and certifies as an exact copy of the original document and contains an official stamped seal from the agency. You may be able to request a certified copy of documents at an embassy or consulate.
Please read the entire section in the link above, just so you're clear as to what's acceptable.
