Colombia's president has accused parts of the country's media of undermining the legitimacy of Colombian democracy.
Former Das head Jorge Noguera is the focus of the allegations
Alvaro Uribe's attack came after two publications alleged there were strong ties between the state security agency, Das, and right-wing paramilitaries.
Activists have long complained of links between state forces and paramilitaries involved in the 40-year internal conflict with left-wing rebels.
Mr Uribe is standing for re-election in May - polls suggest he has a wide lead.
Human Rights Watch strongly criticised his comments.
The US-based group said the president should concentrate on investigating the claims made by the magazines rather than making, what it called, an aggressive attack on the freedom of expression.
The latest allegations against Das emerged last week after Semana interviewed a former official, Rafael Garcia, who is in jail charged with deleting files on paramilitary leaders and drug traffickers.
Mr Garcia reportedly said Das, under the direction of Jorge Noguera, had planned to kill leftists and union activists and had plotted to destabilise the Venezuelan government led by Hugo Chavez.
Das officials allegedly carried out favours for paramilitary leaders, including destroying criminal records.
Mr Garcia is also reported to have accused Mr Noguera - one of Mr Uribe's campaign managers for the 2002 election - of obtaining fraudulent votes for the president.
Mr Noguera resigned as Das director last year amid reports of improper links to paramilitary groups - he was then appointed Colombian consul-general in Milan.
He rejected the accusations on his return to Colombia last week.
He admitted to having held talks on a number of occasions with the top paramilitary chief in the region where he was campaign manager, but said they were related to the peace process.
Speaking on a radio talk show this weekend, Mr Uribe reacted angrily to the allegations.
"This topic is so delicate that the reports gave grounds for rendering the government illegitimate," he said.
"The harm isn't to Alvaro Uribe. The harm is to the legitimacy of Colombian democracy, to a country that for the first time is beginning to see a bonanza of investment."