Northern Ireland's top prosecutor Barra McGrory QC is expected to announce on Wednesday that he's stepping down later this year.
It is thought he will remain as Director of Public Prosecutions until September. It is understood he plans to return to private legal practice.
Mr McGrory was appointed in November 2011 becoming the first Catholic to hold the post.
He has led the prosecution service through challenging times when critics have vocally opposed decisions to charge soldiers over conflict killings.
Mr McGrory has strongly defended his office against claims by Conservative and Democratic Unionist MPs that the authorities are pursuing a witch hunt against former British soldiers.
The Public Prosecution Service (PPS) has mounted five times more cases against alleged paramilitaries than soldiers in five years.
Before Mr McGrory took up the post he was one of Northern Ireland's best known criminal lawyers.
He represented Sinn Fein's Gerry Adams and Martin McGuinness but also loyalist paramilitaries and unionist politicians.
In a number of cases, the DPP has recused himself from prosecution decisions that could be perceived as being linked to his former clients.
The DPP said anyone who understood the legal profession would know lawyers represent anyone who seeks their representation.
Mr McGrory is expected to confirm his decision on Wednesday.
There is no suggestion the move is linked to the criticism he has recently faced.
In December, it was announced two former soldiers are to be prosecuted for allegedly murdering Official IRA commander Joe McCann in Northern Ireland.
The McCann case is thought to be the second military prosecution involving Northern Ireland since the 1990s.
Another former soldier, Dennis Hutchings, who is in his 70s and from Cornwall, has been charged with attempted murder in 2015 in connection with the shooting of John-Pat Cunningham, 27, who had learning difficulties, in Co Tyrone in 1974.
In 1999 paratrooper Lee Clegg was cleared of the murder of a Belfast teenager.
Files on the 1972 Bloody Sunday shootings by soldiers in Derry are being considered by prosecutors.