Pagan Amum was once a staunch ally of the president
The South Sudanese government is withdrawing the case against four top politicians accused of treason, the country's justice minister has said.
The four were accused of plotting a coup against the government - charges they denied.
They held senior posts before falling out with President Salva Kiir.
Former secretary general of the governing SPLM Pagan Amum is among those to benefit, along with two former ministers and a former ambassador.
The charges carried the maximum sentence of death.