BBC director-general Tim Davie has written to staff in India saying the broadcaster “continues to cooperate fully” with authorities after they accused it of tax evasion.

In an internal email, he stressed the BBC “does not have an agenda” and is “driven by purpose”.

Indian tax authorities ended three days of searches of the BBC’s New Delhi and Mumbai offices last week before making the accusation.

Opposition political parties and other media organisations have criticised the searches as an attempt to intimidate the media and noted they came after the BBC aired a documentary which was critical of the Indian prime minister, Narendra Modi.

In an email to its Indian staff, BBC boss Davie said he knew recent weeks had been “incredibly challenging” and that it was “stressful, and sometimes difficult, when the organisation you work for is at the centre of attention”.

He said the corporation “continues to cooperate fully” with Indian Income Tax Authorities.

“We have a big and diverse operation in India and whether you work in the public service or commercial parts of the BBC, we must continue our important work,” he added.

“Nothing is more important than our ability to report without fear of favour. Our duty to our audiences around the world is to pursue the facts through independent and impartial journalism, and to produce and distribute the very best creative content. We won’t be put off from that task.

“I’d like to be clear: the BBC does not have an agenda – we are driven by purpose. And our first public purpose is to provide impartial news and information to help people understand and engage with the world around them.

“It is my job to make sure that you are supported to fulfil this important task and do your work safely.”

On Friday, Davie will speak to the BBC’s Indian employees on a call alongside Jonathan Munro, director of journalism, who will be in Delhi.

They will also be joined by director of the World Service, Liliane Landor, as well as chief executive of BBC Studios, Tom Fussell.

Indian tax authorities spent three days searching the British broadcaster’s offices in New Delhi and Mumbai last week.

India’s Central Board of Direct Taxes later said: “The department gathered several evidences pertaining to the operation of the organisation which indicate that tax has not been paid on certain remittances which have not been disclosed as income in India by the foreign entities of the group.”

It said it found “several discrepancies and inconsistencies” and had gathered “crucial evidence” from statements of employees, digital evidence and documents which would be examined more fully.