New Delhi, May 17 -- The Election Commission of India (ECI) has launched an investigation following the arrest of 25 foreign nationals for allegedly casting votes in the April 23 Tamil Nadu assembly elections, senior ECI officials said on Saturday. According to officials, the arrests occurred at Chennai and Madurai airports as the accused were preparing to board flights out of the country. The accused were intercepted between May 7 and 14 after immigration officials noticed indelible ink marks on the fingers of passengers carrying foreign passports. Nationals from Sri Lanka, the United Kingdom, Canada and Indonesia were among those arrested. "They had used fraudulent Indian ID documents to cast the votes. The indelible ink was noticed on their fingers when they attempted to fly out," the police official said. CEO officials confirmed that cases have been registered and all the accused were produced before a court. State police have registered nine separate cases in connection with the matter. The accused have been booked under Section 172 and Section 318(2) of the Bharatiya Nyaya Sanhita (BNS), along with Section 31 of the Representation of the People Act (RPA), 1950, which punishes false declarations in voter registration forms. Senior ECI officials said the commission has sought reports from returning officers in at least two cities and five districts across the state regarding how the foreign nationals managed to get onto the electoral rolls and cast votes. The inquiry is focused on whether a procedural gap in the Special Intensive Revision (SIR) - a state-wide door-to-door exercise conducted ahead of the polls to clean up electoral rolls - was exploited to keep foreign citizens on the voter list. "The provision allowing family members to submit enumeration forms on behalf of absent voters is suspected to have been exploited. We are investigating all angles and will draw conclusions only after the probe is complete," a CEO official told HT....