Indian police have arrested the son of a junior minister in Prime Minister Narendra Modi’s government after nine people were killed in a demonstration by farmers against contentious agriculture laws in northern India.

Four farmers died on Sunday when a car owned by Junior Home Minister Ajay Mishra ran over a group of protesters farmers in Lakhimpur Kheri, a town in Uttar Pradesh state, officials and farm leaders said.

Farm leaders alleged that Mr Mishra’s son was in the car when it ran over the protesters, but he denied it.

His driver and three members of the ruling Bharatiya Janata Party, who were in a car, were all killed by the protesters by beating them with sticks in the violence that broke out after the incident.

Police officer Upendra Agarwal said on Saturday that Ashish Misra was arrested following day-long questioning in the town after “he failed to furnish any supportive evidence to prove that he was not present in any of the three vehicles that plough through a crowd of farmers killing four of them”.

His father Ajay Mishra said that his son was innocent and that he was not present.

The arrest came a day after India’s top court criticised the state government for not arresting Ashish Mishra against whom a criminal case of murder is being investigated by the police.

On Friday, Mr Mishra made the police wait for hours for questioning before sending a message that he was unwell and could not make it.

Darshan Pal, a farmers’ leader, and Akhilesh Singh, an opposition Congress party leader, demanded the removal of his father from Mr Modi’s government.

Police earlier this week said they had so far arrested six people and filed a criminal complaint against 14 more, including the minister’s son, in connection with the deaths of the four farmers.

The BJP also lodged a criminal complaint against the farmers over the deaths of its members and the car driver, said Arvind Chaurasia, a senior official in charge of the district.

Police also said they recovered the body of a local journalist where violence ensued on Sunday, but did not provide further details on how he was killed.

The violence marked an escalation in ongoing protests against agriculture laws that farmers say will shatter their livelihoods. The protests have lasted since the government passed the laws last September and have been one of the biggest challenges to Mr Modi.

Last week, thousands of farmers gathered at the edges of the capital New Delhi to mark one year of demonstrations. The government says the changes in the laws were needed to modernise agriculture and boost production through private investment.

But the farmers say the laws will devastate their earnings by ending guaranteed pricing and will force them to sell their crops to corporations at cheaper prices.