Prosecution lawyers are bidding to overturn Chile's Supreme Court's ruling that General Pinochet is too ill to stand trial on human rights charges.
The lawyers have claimed that the ruling was unconstitutional on the grounds that it was apparently based on a new penal code which has not yet been adopted throughout Chile.
The ruling was widely considered to have brought an end to the 85-year-old former dictator's legal battle. It is not immediately known when the Supreme Court would take up the complaint.
"We consider that their ruling contains legal errors and abuses," said lawyer Ms Carmen Hertz . "Basically, they have used legal clauses that are not yet effective in Santiago."
The trial could theoretically resume if Pinochet, 85, recovers from his health problems but that possibility appears remote.
Even staunch Pinochet opponents believe the general will now never be held legally accountable for a military operation that killed scores of political prisoners shortly after he seized power in 1973.
Pinochet faced charges of covering up 18 kidnappings and 57 homicides in the so-called "Caravan of Death."
Pinochet suffers from diabetes and arthritis, has a pacemaker and has suffered at least three mild strokes since 1998.