Power of attorney verification

A question for lawyers experienced in property sale transfer law only
A general power of attorney for a property was made in pakistan embassy at washington in 1993 by 7 owners and is being sold now. All owners are not present on the spot.

1) property ki general power of attorney ko kaisay verify kia ja sakta ha ka wo valid ha ya nahi?

2) is property ki purchase ma kia issues ho saktay hain?

Many thanks for your responses