President Carlos Menem in 1999, the year he left office
Argentina's former president, Carlos Menem, has been placed under investigation over his alleged role in a deadly explosion in 1995.
Prosecutors say Mr Menem was responsible for the blast that killed seven people at an arsenal.
They allege Mr Menem was trying to cover up proof of illegal arms trafficking to Ecuador and Croatia in the 1990s.
Mr Menem, president from 1989 to 1999, denies the charges.
The blast took place in the city of Rio Tercero and also injured 300 people.
About 19,000 residents had to be evacuated.
Argentine police have also raided the offices of the German firm Siemens over alleged bribes that were paid to win contracts in the 1990s.
Documents and computers were seized.
Siemens won a contract for national identity cards in 1998 but the order was withdrawn by Mr Menem's successor.
The company has said it is investigating certain payments on its books.
Mr Menem, 78, was last year charged with involvement in the illegal sale of weapons to Croatia and Ecuador.
His 10 years in office were dogged by a string of alleged and proven corruption scandals.