The body of a 60-year-old man was found on Friday evening at Aghindarragh Road, between Augher and Clogher.
An 18-year-old man, arrested in relation to the death, remains in police custody.
The victim's name has not been released by police. A post-mortem examination was due to take place on Sunday.
Michelle Gildernew, Sinn Féin MP for Fermanagh/South Tyrone, has expressed her sadness at the death.
"I would like to express my sympathies to all concerned especially family and friends who are sadly dealing with this news. My thoughts and prayers are with those affected by this death."
Ms Gildernew said the local community was in shock.
Tom Elliott, Ulster Unionist MLA for the area, described the death as a tragedy.
"While the police are obviously investigating the circumstances around this death it is clearly a very difficult time for the family and wider community."