Original Invoice for the ITC

Invoice data appearing in 2B is one of the condition which confirms that tax paid by the supplier to the government as per sec 16(2). However, other 3 conditions under 16 (2) also to be satisfied to avail the ITC.

among other 3 conditions, one condition is the recipient should have a valid invoice to get eligibility to avail ITC.

Legally invoice is required for availing itc but practically itc can be availed even without invoice.

If itc is availed on the basis of gstr2b (without invoice), query may come up during departmental audit if any.

Thank you all sir who responded.
Yes legally required as per law. whether a photocopy or scan copy of invoice is suitable or not.. if not legally, that must be changed by the authorities as there is no chance of wrong ITC credit by the recipient.
it's my view's...

Legally and practically original invoice is required. 

Photo copy is not a valid document.

GSTR-2B only demarcates the highest ITC amount for the month which the supplier can avail.

Invoice is a necessity for availing ITC. 

Department audits have also started so be cautious.