Prosecutors in Colombia have named six politicians they want to question over alleged links to right-wing paramilitary groups.
The paramilitaries are engaged in the peace process
The men are members of President Alvaro Uribe's governing coalition, and include the foreign minister's brother, Senator Alvaro Araujo.
The move comes after three other politicians, also allies of Mr Uribe, were detained earlier this month.
Correspondents say that the scandal has rocked the political establishment.
The four senators and two congressmen are accused of conspiracy to commit crime, the Supreme Court said in a statement.
Four other politicians from northern Colombia are already awaiting trial on charges ranging from funding the paramilitaries to ordering murders.
'Extortion and massacres'
The developing investigation follows the seizure by police of a laptop computer belonging to the right-hand man of one of the leaders of the right-wing United Self-Defence Forces of Colombia (AUC).
The AUC is accused of drug-trafficking, extortion and the massacre of civilians.
Authorities found detailed accounts of the AUC's activities along Colombia's Caribbean coast and its alleged dealings with local politicians.
The paramilitaries were created by landowners and drug-traffickers to combat left-wing rebels and anyone suspected of being their sympathiser.
The AUC is currently engaged in a peace process with the government. This has led to more than 33,000 fighters surrendering their weapons.
Most AUC leaders are now in jail awaiting trials in which they face a maximum of eight years in prison under the terms of the peace process.