It will also sustain anti-Hezbollah sentiment within the March 14 alliance, especially among Lebanese Sunnis who are still smarting from their drubbing at the hands of Hezbollah's fighters during street clashes in Beirut a year ago.
"My main worry is that March 14 will use the story against Hezbollah and that would be tantamount to a declaration of war and will be a disaster for Lebanon," says Amal Saad-Ghorayeb, a Lebanese expert on Hezbollah.
However, March 14 leaders seem determined to ignore the story.
Walid Jumblatt, chieftain of the Druze faction of the coalition, compared Der Spiegel's revelations to the April 1975 shooting of bus passengers in the Beirut suburb of Ain Rummaneh that triggered a 16-year civil war here.
"Beware of rumors and press leaks, they could damage the work of justice and provoke discord and sedition," said Mr. Jumblatt, formerly an arch-critic of Hezbollah who lately has softened his tone.
Hani Hammoud, a spokesman for Saad Hariri, Rafik Hariri's son and political heir, also played down the story.
"We do not comment on any information regarding the tribunal unless it is officially stated by the tribunal," he said.
Spiegel details gripping, but analysis questionable
Der Spiegel claimed that Lebanese investigators had traced cellphone communications during the period just before Hariri's death to pinpoint an initial group of eight suspects. A "second circle of hell" of some 20 cell phones was subsequently identified that were used in close proximity to the first eight phones. The cell-phone numbers of the second group were all traced to Hezbollah militants, with the alleged mastermind named as Hajj Salim, the alleged head of Hezbollah's "special operations unit."