Ranjeet Mandal, the alleged mastermind of the kidnapping of two sons of a Delhi businessman last month, was arrested on Monday from his village in Lakhisarai district.

Acting on a tip-off, a police team conducted a raid at Baudha Nagar village in Lakhisarai, around 140km east of Patna, on Monday morning and apprehended Mandal, who had come to attend a relative's last rites. "We are completing legal formalities to produce Mandal in the local court," Lakhisarai superintendent of police Ashok Kumar said.

Kumar, who is also part of the special investigation team investigating the kidnapping case, said Mandal was absconding after his name figured in the abduction of Suresh Sharma and Kapil Sharma from the Patna airport premises on October 21 this year. The Sharmas have their business in Delhi, Haryana and Uttar Pradesh.

The Lakhisarai SP said Mandal, also called Ranjit Don, had masterminded the kidnapping of the duo and demanded Rs 5 crore as ransom. Mandal, the kingpin of the inter-state gang, had lured the brothers to Bihar on the pretext of helping them bag a contract worth Rs 200 crore.

However, the brothers were rescued by a joint team of the Central Reserve Police Force and the personnel of Patna and Lakhisarai police from Simratali in the Kajra forests following an encounter with the kidnappers on October 26. Later, two members of the gang - Lallan Gupta and Manoj Yadav - were arrested by the police.

City superintendent of police (Patna central) Chandan Kushwaha, who is holding additional charge of senior superintendent of police, said Mandal would be taken on remand. "Since the FIR was lodged in Patna's Airport police station, the Patna police would take Mandal, the prime accused, on remand for interrogation," Kushwaha told The Telegraph.

Mandal, whose name had earlier figured in the kidnapping of two affluent persons from Haryana and Uttar Pradesh, stepped into the world of crime in 2008. "He is a professional kidnapper and has spread his tentacles in different states," Kushwaha said.

Last week, a police team had visited Calcutta to apprehend Mandal but he could not be arrested. The team was sent to Calcutta following information provided by Lallan that Mandal was hiding in the Bengal capital. "His interrogation will throw more light on the case," Kushwaha added.

Police sources said Mandal was proving to be a hard nut to crack during initial interrogation by the Lakhisarai police. "He put the onus on his associate Lallan Gupta, who is lodged in Beur Central Jail," an investigating officer said.