NEW DELHI: India's federal police have arrested a leader of the main opposition Bharatiya Janata Party over his alleged role in the murder of an anti-corruption activist, authorities said Wednesday.

 The Central Bureau of Investigation (CBI) arrested Dinu Bogha Solanki, an MP from western Gujarat state, for allegedly conspiring to kill Amit Jethwa, who sought to expose illegal mining in the state.

 "The MP was called for questioning by the CBI (on Tuesday) and after detailed interrogation, he was arrested in the evening," the CBI said in a statement.

 Jethwa, a 34-year-old Right to Information activist, who was campaigning under India's freedom of information laws, was shot dead in 2010 by two motorcycle-borne assailants near the High Court in Ahmedabad.

 He had accused Solanki of being involved in illegal mining around the protected Gir Forest region in Gujarat and had been campaigning to expose his activities, the CBI said.

 Jethwa's killing led to a public outcry and calls for bringing in new legislation to protect whistleblowers.

 In recent years, incidents of intimidation, violence and murder have been reported against those seeking to expose corruption in government ranks.

 In one of the most high-profile cases, a project director with the National Highways Authority of India was killed in 2003, and last year, a Karnataka state official was murdered over land allotment issues.

 Corruption is a hot topic as India gears up for a general election in 2014, with the ruling Congress party battling a string of bribery scandals.

 Some 160 lawmakers in the national lower house of parliament and over 1,400 state legislature politicians from across the political spectrum are facing a range of criminal charges, according to campaign group the Association for Democratic Reforms.