About 40% of the detectives appointed to reinvestigate unsolved murders in Northern Ireland left within the first year, it has been revealed.
The Historical Enquiries Team (HET) was set up to investigate unsolved murders in NI between 1969 and 1998.
HET director Dave Cox revealed the high turnover of staff to the Northern Ireland Affairs Committee.
He said that the stress of living away from home was a major reason for detectives leaving.
"With people living away from home in the week, coming to Northern Ireland, living in lodgings, going home on a Friday, we tend to find that after about a year or so many of them leave," he said
In the first year the team had a 40% turnover in staff, while it was about 29% last year. There are currently 180 staff, up from 80 two years ago.
A spokeswoman for the HET told the Press Association many members only signed up to the job for a limited period because of the travel.
"Many are attracted to work for HET because of the unique nature of the challenge and a desire to help families if possible," she said.
"However, the nature of the work is also very challenging and some people find that after an extended period, they do not want to experience any more of the trauma involved in these cases.
"HET currently have a mentoring system in place whereby experienced staff help new arrivals with all aspects of HET work."