Police spokesman Cornel Iures said the journalist's remains were found near the village of Pischia, 16 miles northeast of the western Romanian city of Timisoara, where Costinas had lived and worked prior to his disappearance, The Associated Press reported.
Iures said the corpse was positively identified after Costinas' dental records were reviewed and the journalists' mother identified articles of clothing and other personal possessions found alongside the corpse. The cause of death is unclear.
"We mourns the loss of our colleague Iosif Costinas," said Joel Simon acting director of the Committee to Protect Journalists (CPJ). "We express our deepest condolences to his family and friends and call on the Romanian authorities to aggressively investigate this case."
Costinas' journalism focused on highly sensitive political issues, including a number of unsolved murders that occurred during the 1989 anti-communist revolt, which began in Timisoara, as well as the continued presence of communist-era secret police agents in the government.
Prior to his disappearance, Costinas was also working on a book about organized crime, according to The Associated Press.
Malin Bot, a journalist for the independent Timisoara daily Ziua de Vest who has investigated Costinas' disappearance, told CPJ that a group of Costinas' childhood friends recently published his book post-humously.
"Journalists in Timisoara are angry and suspicious about Costinas' death because the people who did this could go after anyone of us...I could be next," Bot said.