An Italian businessman named in an arms bribery case in India has been held in Argentina, Indian officials say.
Ottavio Quattrocchi is on Interpol's wanted list
A statement by the Indian Central Bureau of Investigation (CBI) said that Ottavio Quattrocchi was taken into custody on 6 February.
The CBI has asked the Indian foreign ministry to send an extradition request to the government of Argentina.
The Bofors corruption case is one of the highest-profile and longest-running in India, lasting nearly 15 years.
CBI officials say that a formal extradition request needs to be made within 30 days of Mr Quattrocchi's detention.
Illegal commissions were allegedly paid on the Bofors guns
At the moment India has no extradition treaty with Argentina.
Swedish firm AB Bofors was alleged to have paid $1.3bn in bribes over the sale of 400 Howitzers to India in 1986.
The Indian authorities say Mr Quattrocchi was the intermediary in the deal, and received $7m in bribes and other illegal payments.
The Indian authorities have for much of the last decade been trying to get Mr Quattrocchi extradited to India.
Interpol has issued a notice against him.
Mr Quattrocchi says he is innocent, and is the victim of a political vendetta in India because of his links to the Gandhi family.
The Bofors case led to the election defeat of former Prime Minister Rajiv Gandhi in 1989, two years before he was assassinated.
In 2004, Mr Gandhi was posthumously cleared of any wrongdoing in the deal, which was signed when he was in office.
In May 2005, three of the billionaire Hinduja brothers were acquitted in the case.
The Delhi High Court threw out all charges against Britons Srichand and Gopichand Hinduja and Swiss citizen Prakash Hinduja for lack of evidence.