Singh is a close relative of a BJP leader in Sultanpur. He is posted in Ghazipur where he works as a train ticket examiner in Ghazipur.
Police is likely to hold a press conference on his arrest and the case.
The shocking murder of Saroj, a second year LLB student, took place publicly and barely 500 metres from a police station near the University of Allahabad.
He was bludgeoned by four persons with iron bars and chairs on Friday. The gory visuals had gone viral on social media sparking public anger. Student groups in Allahabad went on a rampage in parts of the city, torched a bus and also laid siege to the house of District Magistrate Suhas L.Y.
Killing of Dilip Saroj
Police claimed the attack followed a spat that Dilip and some friends had with another group at a restaurant.
Amit Upadhyaya, the owner of the restaurant, appeared to suggest that the attackers had been called by the group which had an altercation with Dilip and his friends. "The attackers had come in an SUV. The friends of Dilip, who were also injured, took him to a nearby hospital where he was declared brought dead," Upadhyaya said .
Richa Singh, a former president of the Allahabad University Student Union, told the Telegraph, Calcutta: "Serious crimes are taking place near the university every day. The police don't take action till the media pick up the cases."
BJP’s narrow, casteist politics of hatred: Mayawati
BSP chief Mayawati had sent her state unit chief Ram Achal Rajbhar to meet the bereaved family in Allahabad, asked the state government to ensure the immediate arrest of the culprits and help to the family. She blamed the ruling state government for pursuing politics of hatred.