Manipulated videos are taking centre stage as campaigning heats up in India’s election, with fake clips involving two top aides of Prime Minister Narendra Modi triggering police investigations and the arrest of some workers of his rival Congress party.

In what has been dubbed as India’s first AI election, Modi said last week fake voices were being used to purportedly show leaders making “statements that we have never even thought of”, calling it a conspiracy “to create tension in society.”

Indian police — already investigating the spread of fake videos showing Bollywood actors criticizing Modi — are now investigating a doctored online clip that showed federal home minister Amit Shah saying the ruling Bharatiya Janata Party will stop certain social guarantees for minorities, a subject sensitive for millions of voters.

Shah retorted on X, posting his “original” and the edited “fake” speech and alleging — without providing any evidence — that the main opposition Congress was behind the video it created to mislead the public. The minister said “directions have been issued to the police to address this issue.”

The arrest has sparked protests from Congress workers with many posting on X using the #ReleaseArunReddy tag. Congress lawmaker Manickam Tagore said the arrest was an example of “authoritarian misuse of power by the regime.”

Congress’ head of social media, Supriya Shrinate, did not respond to messages and an email seeking comment.

With nearly a billion voters and more than 800 million internet users, tackling the spread of misinformation is a high stakes job. It involves round-the-clock monitoring by police and election officials who often issue take down orders to Facebook and X as investigations start.

In India’s most populous state of Uttar Pradesh, more than 500 people keep tabs on online content, flagging controversial posts and coordinating with social media companies for their removal when needed, police chief Prashant Kumar told Reuters on Saturday.

Another fake video that sparked a storm last week showed Yogi Adityanath, the state’s chief minister, criticizing Modi for not doing enough for families of those who died in a 2019 militant attack. Though fact checkers said the video was created using different parts of an original clip, state police called it an “AI generated, deepfake”.

Using internet address tracking, state police arrested a man named Shyam Gupta on May 2 who had shared the fake video post on X a day earlier, receiving over 3,000 views and 11 likes.

The police have accused Gupta of forgery and promoting enmity under Indian law provisions that can carry a jail term of up to seven years if convicted. Reuters could not reach him as he is currently serving a 14-day custody period.

“This person is not a tech guy. Had he been tech savvy, arresting him quickly would not have been possible,” said police officer Kumar.