The cards meant for distribution to theowners had not been apparently delivered by the postoffice concerned, the officials said.
Some of the local people in Thiruthurapoondi managed to get theiraadhar card from the dump, they said.
The cards, bundled in jute bags and abandoned, were found by the children playing in the riverbed.
The revenue officials rushed to the spot and recovered the cards.
The cards belonged to the residents of Kattimedu, Aathirangam, Vadapathi and Sekkal villages, the revenue officials told newsmen.
The cards had been printed two years ago, the officials said.
The people of the area would have got the government scheme benefits by quoting the application number.
The cards were without cover.
A case has been registered on a complaint from the the village administrative officer, the police said.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)