If you go through the forum, this has been discussed.
Its advisable to take Bank Statement from Bank Directly with stamp and everything. If you cant include the original statement. Then you Print outs of online statement, and also the Print out of the Bank Branch's contact, where you have account. There is no mention of the "Proof of funds" have to be an official original statement. But you have to prove it.
Many have applied with online statements and been accepted. I have also applied with some part of the POF as online statement with Bank's contact included. My appli is new, so I cannot say 100% as to what happens.
Rest is probably at the officer's experience, discretion. They can call up Banks and verify your details anytime, though I guess its done mostly at Visa Office level, but, you never know.