President Cristina Fernandez de Kirchner has announced plans to disband Argentina's intelligence agency.
In a TV address, she said she would draft a bill to set up a new body.
Ms Fernandez said the intelligence services had kept much of the same structure they had during the military government, which ended in 1983.
The move comes after the mysterious death of prosecutor Alberto Nisman - hours before he had been due to testify against senior government officials.
He had been investigating the bombing of a Jewish centre in the capital in 1994 which left 85 people dead.
Argentina's Intelligence Secretariat (SI, also known by its previous name Side)
- Founded in 1946 by General Juan Peron as a civilian intelligence agency
- Mission was to provide both internal and foreign intelligence
- Evolved into a secret police force during Argentina's Dirty War (1974-1983)
- Used by military junta to track down opponents and spy on "subversives", including trade union and other left-wing activists
- Survived the transition to democracy in 1983
- Critics allege SI has since been used to monitor the activities of critical journalists, politicians, judges and prosecutors
- No official staffing figures available - but analysts believe it has grown in influence and size in the past decade
- Led since December 2014 by Oscar Parrilli following the resignation of Hector Icazuriaga after 11 years
Mr Nisman, 51, had accused several senior government figures - including President Fernandez and Foreign Minister Hector Timerman - of involvement in a plot to cover up Iran's alleged role in the bombing.
"I have prepared a bill to reform the intelligence service," President Fernandez said, adding that she wanted the proposal to be discussed at an urgent session of Congress.
"The plan is to dissolve the Intelligence Secretariat and create a Federal Intelligence Agency," she said that a new leadership should be chosen by a president but would be subject to a Senate approval.
"Combating impunity has been a priority of my government," she added.
Mr Nisman was found dead on 18 January in his flat in Buenos Aires. A gun was also discovered there.
Investigators initially said they believed he had committed suicide, but later said they could not rule out homicide or "induced suicide".
Ms Fernandez has said she is convinced Mr Nisman's death was not suicide.