Police in Kerala have sought legal advice on a complaint about a movie teaser that is sparking controversy in the southern Indian state.

In the teaser - for an upcoming movie called The Kerala Story - an actress claims her character is one among 32,000 women from the state who were "converted" into Islamic terrorists.

Some politicians from the state have called for the film to be banned.

A journalist has written to the state's chief minister seeking an inquiry.

The office of the chief minister referred the letter - written by Arvindakshan BR - to the police.

"Investigation has started. We have sought legal opinion on the letter as to what action can be initiated," said Sparjan Kumar, police commissioner of Thiruvananthapuram, the capital of Kerala.

In the teaser, a burkha-clad woman says that her name was Shalini Unnikrishnan and she had wanted to become a nurse.

"Now I am Fatima Ba, an IS terrorist in a jail in Afghanistan," she says, adding that there are "32,000 girls like [her] who have been converted and buried in the deserts of Syria and Yemen".

"A deadly game is being played to convert normal girls into dreaded terrorists in Kerala and that too in the open," she says.

The teaser has been viewed more than 440,000 times on YouTube in the past six days and has received both criticism and praise.

Adah Sharma, the actress, tweeted the teaser of the movie with the hashtag #TrueStory. The film's producer, Vipul Shah, did not respond to the BBC's messages.

Mr Arvindakshan, the journalist, told the BBC that he has asked for an inquiry and for the filmmakers to produce evidence because he was outraged by the claims in the teaser.

"Some cases may have happened but 32,000 is an unbelievable number,'' he said.

In an 2021 interview with Citti Media - a media production company - the film's director said that he arrived at that number based on figures given to the Kerala assembly by former chief minister Oommen Chandy.

Mr Sen claimed that Mr Chandy had said that "every year approximately 2,800 to 3,200 girls were taking up Islam" and so, it worked up to 32,000 in 10 years.

However, Indian fact-checking news website Alt News said in a report that there was "no evidence" to back the claim.

It found that Mr Chandy in 2012 had said that 2,667 young women had converted to Islam in the state since 2006, without mentioning an annual figure.

In 2016, a group of 21 people from Kerala had left the country in batches to join an affiliate of the Islamic State jihadist militant group.

One of them, a student, had converted to Islam before getting married. She was eight months pregnant when she left the country.

In 2021, after the Taliban returned to power in Afghanistan, Indian officials said four women from Kerala who had joined the Islamic State were in jail there.

"One needs to check the records but our estimate is that there are not more than 10-15 women who have got converted and left to join the IS from Kerala since 2016," a police official, who spoke on condition of anonymity, told the BBC.

Mr Arvindakshan says he has also written to the Central Board of Film Certification, state film certification boards as well as India's minister for information and broadcasting Anurag Thakur. He has not received any response yet.

"This film is against the unity and sovereignty of India and tarnishes the credibility of all intelligence agencies of India," he said.

The film's teaser has also triggered a political controversy in Kerala.

Congress party leader VD Satheesan called it a "clear case of misinformation" and claimed that the film was made to "tarnish the image of Kerala" and "spread hatred among people".

Lawmaker of Kerala's governing Communist Party of India (Marxist) John Brittas on Wednesday wrote a letter to federal home minister Amit Shah, asking him to take stringent action against the filmmakers.

However, K Surendran - a leader of the Bharatiya Janata Party (BJP) - criticised the Kerala government for filing a case against the filmmakers.

He said the chief minister "should have the guts to act against the IS recruiters in Kerala".