"We have issued a notice to the Congress candidate for campaigning beyond the stipulated time fixed. She was given time to reply by tomorrow," Chief Election Officer F R Kharkongor told PTI.
He said the EC officer concerned in South West Garo Hills district had issued the notice to the candidate.
The election agent of the Congress party has already submitted a reply to the returning officer Pravin Bakshi today, a party spokesperson said.
The bypoll was necessitated following the demise of P A Sangma earlier this year.
Meanwhile, in view of the IMD forecasting heavy to very heavy rainfall in certain pockets in Meghalaya along with Arunachal Pradesh and Assam in the next few days, South West Garo Hills district election officer Ram Singh alerted the polling personnel, most of whom have already departed for their respective polling stations, to take necessary measures.