Forensic experts have begun a high-tech search for the unmarked grave of an Irish Republican Army victim, a long-unresolved part of Northern Ireland's peace process.

Lead investigator Geoff Knupfer said Monday that ground-penetrating radar and a sniffer dog would be used to try to find the remains of Joe Lynskey, a Belfast IRA member who disappeared in 1972.

Knupfer's team is surveying a six-hectare (15-acre) field in County Meath northwest of Dublin near where remains of another long-missing IRA victim were found Oct. 1. Knupfer says he believes the IRA dumped several bodies in Meath bogland in the 1970s.

The IRA admitted in 2010 that it killed Lynskey, and IRA intelligence officer. The outlawed organization said it punished Lynskey for having an affair an imprisoned IRA member's wife.