The Election Commission (EC) has rejected West Bengal Chief Minister Mamata Banerjee’s allegations of bias levelled by her against the poll body over transferring of four IPS officers in the state, sources said on Sunday.

In its reply, EC said that it has always taken decisions in the "interest of free and fair polls" and "does not need to prove its credibility."

Mamata Banerjee on Saturday had termed EC's decision to transfer four West Bengal IPS officers, including Kolkata Police Commissioner Anuj Sharma and Bidhannagar Police Commissioner Gyanwant Singh ahead of the Lok Sabha Election 2019 as "highly arbitrary, motivated and biased towards BJP." They were also barred from poll duty.

Mamata said that the flow of events raises "strong doubts" over the Commission`s functioning to conduct free and fair polls in the state.

EC's decision came days after state BJP leaders alleged that fair elections would not be possible in West Bengal, as both Sharma and Singh were spotted at Mamata's dharna last month to protest CBI's action against the then Kolkata police commissioner Rajeev Kumar in connection with its probe in the Saradha scam.

"The decision of the Commission is highly arbitrary, motivated and biased. We have every reason to believe that the decision of the Commission is at the behest of the ruling party at the Centre (BJP)," read Mamata's letter to the EC.

"This flow of events gives rise to strong doubts whether the Commission is functioning as per its constitutional mandate of conducting free and fair elections or working in a manner to appease the ruling BJP at the Centre," she added.

The poll body on Friday removed Sharma, Singh and two Superintendents of Police -- Shyam Singh of Birbhum and P.S. Selvamurugan of Diamond Harbour police district.

In a statement, Chief Secretary Malay De said Rajesh Kumar, who was till now ADG and IGP - Pollution Control Board, would take over as the new city Police Commissioner, while Natarajan Ramesh Babu, appointed as ADG and IGP - Operations, will take over as Bidhannagar Police Commissioner.