According to the Election Commission sources 74.89 per cent votes were recorded till 3 PM.
With the polling continuing till 5 pm the final vote percentage is awaited.
The EC said the election was by and large peaceful and it is looking into complaints by the opposition parties.
Polling in the constituency is being held amid tight security with eight companies of central forces deployed, he said.
The opposition CPI(M) and BJP have accused the ruling Trinamool Congress of driving away their election agents from the polling booths, which was denied by TMC leader and Rajya Sabha MP Manas Bhunia.
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"The election results will not reflect the real mandate of the people. The people of Sabang could not vote freely and fairly due to the terror tactics of TMC," he said.
Ghosh's view was echoed by CPI(M) and Congress.
"The TMC has been doing this in each and every election. They know that they will lose Sabang and that is why they resorted to violence," Leader of opposition and state Congress leader Abdul Mannan said.
The TMC, however, denied the allegations and said the people have voted in favour of Chief Minister Mamata Banerjee's developmental politics.
TMC has fielded Gita Rani Bhunia, wife of Manas Bhunia, a former Congress MLA who had defected to the Mamata Banerjee-led party earlier this year necessitating the byelection.
Bhunia had won the seat in last year's assembly polls.
The BJP has nominated Antara Bhattacharya, while the Congress has fielded Chiranjib Bhowmick, a local leader. Rita Mandal of the CPI(M) is contesting as a Left Front candidate.