Kanpur: A 47-year-old widow was arrested Thursday after her alleged lover and his brother were rounded up for allegedly murdering her 22-year-old son to claim Rs 40 lakh from four life insurance policies taken in his name, UP police said Thursday. Mamta Devi allegedly conspired with Mayank Katiyar, 33, and his brother Rishi Katiyar, 28, to kill her son Pradeep Sharma on the night of Oct 26-27 in Angadpur village of Kanpur Dehat.SP Shraddha Narendra Pandey said Pradeep, who worked in Andhra, had returned home to celebrate Diwali when his mother. “Mamta and Mayank planned the murder to claim the insurance money,” Pandey said.Police said Mayank and Rishi picked Pradeep up on pretext of having dinner and drove him to a deserted stretch where they allegedly attacked him with a hammer. His body was dumped on the highway to stage it as a road accident and cash in on the insurance policies purchased by Mamta in her son’s name, police said.