1) has seller lodged police complaint about loss of original documents .
2) if original sale deed between builder and seller is present you may not face any problem .
3) but original payment receipt is necessary as it indicates proof of payment .
4) check whether builder can issue duplicate payment receipt to seller .
5) whether bank is willing to disburse loan even in absence of these documents .
6)you can call off the deal if seller does not have original documents