Execution of power of attorney post sale deed for legal purposes

Sir, My mother has given her power of attorney to a relative in 2006 which was duly registered for sale of our agricultural land and to get permission for NA. The sale was executed in 2010 and registered sale transaction was executed by the GPA holder on our behalf, however, we have never received any consideration for the same. Keeping absence of consideration aside, it came to our knowledge that the Buyer has faced some issue with the Municipalities related to this land and as original owner of the land, our name is used by the buyer in the "Petitioners" along with him, in which I believe the GPA holder has allowed and assisted. Now my queries are: 1. Is the Register Power of Attorney that was given in 2006 still valid after the changed in September 2011 related to GPA? In other words, can the GPA holder still operate on our behalf on any legal and land related operations? 2. Is there any harm if our name is used as Petitioners in the case, without our consent? Can we get any protection in that case?. Really appreciate any assistance in this regards.