The NRIs have been asked to prove ownership by the officials though there are no disputes.
Sources said the officials were doing it after being prodded by land sharks who have an eye on the prime property.
Mr M. Ramakrishna, a US-based business analyst, is one among these NRIs. He is now frequently flying to the city to protect his ancestral property in Ranga Reddy district.
Though the district revenue officer had approved his ownership of the land in 1975, certain realtors have raked up the issue again.
The Shamshabad tahsildar issued a notice to Mr Ramakrishna in April asking him to prove ownership.
Since then, Mr Ramakrishna has been periodically making rounds of the revenue offices Certain realtors close to a Congress leader are said to be behind the tahsildar's move.
Tahsildars are not empowered to reopen cases that have been disposed of by the district revenue officer, joint collector and collector.
"I fail to understand how a tahsildar can act in such a manner," said Mr Ramakrishna. "I have petitioned to the higher authorities but so far the case has not been settled."
Incidentally, Ranga Reddy revenue authorities had recently destroyed land records which were 30 years old.
Sources said some tahsildars were re-opening old cases on the pretext of following Chief Minister Y.S. Rajasekhar Reddy's order to find illegal beneficiaries of assigned land.
A top district official said he had got complaints against the junior revenue officials and was examining them.