Police say Mr Sharma is "a big catch" (Photo: Dilip Verma)
Police in the Indian state of Jharkhand say they have arrested an agricultural scientist and his wife who are believed to be senior Maoist leaders.
Ravi Sharma and his wife B Anuradha were arrested from the forests near Hazaribagh town last week.
A rebel spokesman in Jharkhand described the arrests as "illegal".
Meanwhile police in the state of Chhattisgarh say they have arrested nine suspected Maoist rebels. They said four pistols had been recovered.
Last month, police arrested top Maoist leader Kobad Ghandy from Delhi.
Maoists, also known as Naxalites, are active in more than one-third of India.
The rebels say they are fighting for the rights of the poor and landless.
Prime Minister Manmohan Singh has said that Maoist insurgents pose the biggest security threat to India.
The couple held in Jharkhand were involved in many recent acts of violence in that state and in the state of Bihar, police said. They described the arrests as "a good catch".
Ravi Sharma, 50, is a member of the central committee of the banned Communist Party of India (Maoist), police say.
Mr Sharma, who also goes by the name of Ashok, is in charge of the Bihar-Jharkhand special area committee, they say.
His wife, B Anuradha, also known as Rajitha, is the head of the women's wing of the party, police say.
The couple come from Andhra Pradesh but have been working in the states of Bihar and Jharkhand.
"At present, his main work is to give military-related training and hold camps and distribute literature to his party men," The Reuters news agency quoted senior Hazaribagh police officer Pankaj Kamboz as saying.
"Apart from Bihar, we are investigating in West Bengal and Orissa where he is in touch with fellow rebels," he said.
"This was a good catch. He is an intellectual and was the mastermind in many of the cases," Mr Kamboz added.
Police say they have also recovered some weapons and ammunition from Mr Sharma's possession.
But Jharkhand rebel leader Koteshwar Rao was strongly critical of the arrests.
"The arrests were made on 10 October. Why didn't the police produce them in court within 24 hours as stipulated by law?" Mr Rao said on the BBC Hindi service.
The couple's arrest comes barely a month after the arrest of Kobad Ghandy, a top Maoist leader who reportedly came from an upper class background before he become one of the country's most wanted rebels.
Mr Ghandy - a foreign educated urbanite - served the Maoist cause with "discipline and perseverance" for over 30 years - with over a decade spent underground in various tribal areas, his friends say.