In disputes regarding the validity of a property transfer, the burden of proof lies primarily on the party asserting the validity of the transfer. This means that if one party claims that a property has been lawfully and validly transferred (through sale, gift, will, etc.), they must prove that the transfer was executed in accordance with the law.

Under Indian law, particularly the Indian Evidence Act, 1872, the relevant principles are:

Section 101: "Whoever desires any court to give judgment as to any legal right or liability dependent on the existence of facts which he asserts, must prove that those facts exist."
So, the person who asserts the validity of a transaction must prove it.

In the context of property transfer, the person claiming ownership through transfer must usually prove:

The existence and authenticity of the transfer document (e.g., sale deed, gift deed),

That the transfer was done voluntarily and with valid consideration (if required),

Compliance with legal formalities such as registration under the Registration Act, 1908 and, where applicable, payment of stamp duty.

In cases involving allegations of fraud, coercion, or misrepresentation, the burden may shift. For instance, if a person claims that a property transfer was made under undue influence or fraud, they must prove those allegations. However, if there is a fiduciary relationship (e.g., between parent and child or lawyer and client), the burden may shift to the transferee to prove that the transfer was made fairly and without pressure.

In case of gifts, especially from elderly or ill persons, courts often scrutinize the circumstances of the transfer, and the donee may be required to prove that the gift was made voluntarily and with full understanding.