The Union Health Ministry has applied filters in its Co-Win platform in poll-going states and a union territory to exclude the picture of the prime minister from the COVID-19 vaccine certificates, sources said on Thursday.

In a letter to the Election Commission on March 9, Union Health Secretary Rajesh Bhushan is learnt to have said that "technical measures to comply with the directions of EC have been explored promptly."

"Necessary filters" in Co-WIN have been applied for the vaccination centres situated in the four states of Assam, Kerala, Tamil Nadu, Bengal and Union Territory of Puducherry, as suggested by the Commission.

Following a complaint by the Trinamool Congress, the Commission had asked the health ministry to follow the model code in letter and spirit.

It had suggested use of filters in the Co-Win platform to exclude the picture of the prime minister in COVID-19 certificates being given to people in the poll-bound states and the UT.

Sources aware of the correspondence between the Election Commission and the ministry said the panel has not referred to any individual or personality but had asked the health ministry to follow the provisions of the model code in letter and spirit.

The poll panel had suggested use of filters to comply with the provisions of the poll code.

The model code had come into force in Assam, West Bengal, Tamil Nadu, Kerala and Puducherry on February 26, the day the EC announced polls in these four states and union territory.