NEW DELHI: The Election Fee has instructed presiding officers of all cubicles, significantly in West Bengal, to test and make sure that all candidate buttons on digital voting machines (EVMs) are clearly seen and never coated with tape, glue or some other materials, together with color, ink, fragrance or chemical that may compromise the secrecy of votes.Instances during which candidate buttons are discovered with the above anomalies are prone to fall beneath tampering or interference with digital voting machines (EVM), which is an electoral offence.EC officers on Tuesday stated the fee won’t hesitate to take prison motion or order a repoll in such circumstances.Wherever cases of tampering are observed, the presiding officer will instantly inform the sector officer or returning officer.