India's Supreme Court has sought an explanation from the government about the arrest of an Italian businessman named in a major bribery case.
Ottavio Quattrocchi is on Interpol's wanted list
The court asked why it was not informed of the detention of Ottavio Quattrocchi in Argentina on 6 February when it heard the case six days later.
The Bofors corruption case is one of the highest-profile and longest-running in India, lasting nearly 15 years.
Authorities say Mr Quattrocchi took $7m in bribes in the deal, which he denies.
The businessman says he is the victim of a political vendetta in India.
On Monday the court gave the federal government and its top detective agency, the Central Bureau of Investigation (CBI), a week to explain why it was not informed of Mr Quattrocchi's arrest.
News of his arrest emerged only last week.
A CBI team is going to Argentina on Wednesday to press for Mr Quattrocchi's extradition, officials said.
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.
Illegal commissions were allegedly paid on the Bofors guns
Interpol has issued a notice against him.
Mr Quattrocchi says he is a 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.