Kolkata: The district magistrate and the SP of Bankura submitted their report to EC on Tuesday on the allegation of an attempt to tamper with EVMs kept in the strongroom in Bishnupur. The report said prima facie, there was no proof of tampering. An official said the report stated that the lock of the strongroom was intact and was examined by candidates.However, why some police officers had gone to the strongroom was being investigated, the official said. tnn