Please do understand the meaning of power of attorney
A power of attorney is an authority given by one person to another, authorising him to act on his behalf. According to the Power of Attorney Act 1882, power of attorney 'includes any instrument empowering a specified person to act for and in the name of the person executing it'.
Immovable property can be legally transferred only by way of a deed of conveyance which is duly stamped under the provisions of the Stamp Act applicable to the state in which such property is situated, as well as registered under the provisions of the Registration Act, 1908.
So in your father's life time ,he has every right to transfer the property to any person.If he is not transfer the property in his life time ,after the death the original owner has right to transfer the same. Actually by creating a POA ,the ownership and title over the property is not transferred from original owner to POA holder. POA holder got the power to transfer the title to on behalf of original owner.
When i read your words it seems that your father had given the sale consideration through his friend. It can be used as evidence in favour of you.But not too much hops are not available