The DPP is the only person who can decide what impact the ill-health of former State Pathologist Prof John Harbison will have on future prosecutions, the Taoiseach, Mr Ahern, said today.
A retrial for the manslaughter of Dublin student Brian Murphy outside Anabel's Nightclub in August 2000 collapsed on Monday because Prof Harbison, 71 was unable to give court evidence due to a degenerative illness.
A murder charge in another case was reduced to manslaughter last month because Prof Harbison was also unable to attend as a witness in the retrial.
In the Dail, Labour leader Pat Rabbitte today asked Mr Ahern how many cases would be affected by the former State Pathologist's illness.
During Leaders' Questions he accused Mr Ahern of trying to 'muddy the waters' by claiming the State Pathologist was independent of the Minister for Justice.
"The fact of the matter is that the State Pathologist is directly recruited or contracted to the Justice Department and the Justice Minister is responsible, not the DPP."
But Mr Ahern said he didn't have the authority to give Mr Rabbitte an assurance that no prosecution cases would or would not be affected by Prof Harbison's ill-health.
"I can't say that. That is not my responsibility. A decision in relation to proceeding with a trial or retrial is exclusively a matter for the DPP. He is an independent officer who makes his own independent assessment applying in each case.
He added: "I couldn't do that and I wouldn't even make such a stupid guess at something like that."
"It is not the function of this House or any entity to seek to influence the decisions of the DPP. I'm not going to get into that.
"What implications, if any, arise from Prof Harbison's condition, is a matter for assessment by the DPP on a case by case basis. "If somebody else can make an assessment of what might happen in the Court of Criminal Appeal in a year's time or two year's time, on a case or murder that happened five years ago, I'm not going to go down that road."
The DPP, James Hamilton never discusses individual prosecutions nor gives his reasons for any decisions made. Government sources insisted last night that Prof Harbison had continued until recently to give competent and lucid court evidence about post mortems he carried out before he formally retired in early 2003.