A young Bahraini Shiite missing for 48 hours has been found dead, sparking conflicting reports Saturday over his death as the government said he had drowned while the opposition insisted he died in custody. \"On Friday, police received a call reporting a dead body found at Amwaj islands. Police responded to the scene and it was determined that the body was that of Yousif Ahmed Abbas,\" the interior ministry said in a statement. \"An autopsy performed by the medical examiner determined that Abbas (missing since Wednesday) had been dead for more than 24 hours and that the cause of death was drowning,\" said the English-language statement received by AFP. But Bahrain\'s main opposition formation, Al-Wefaq, said the 24-year-old\'s family had been told by a police office that was under detention at the time of his death. \"Security services have informed his family that the victim was being interrogated,\" Al-Wefaq member and former MP Matar Matar told AFP. \"We demand that a neutral non-Bahraini commission investigates this case and other cases concerning the killing and targeting of citizens due to the total lack of confidence in the integrity of Bahraini security services and judiciary,\" the party said on its website. But the interior ministry said a search was launched immediately after the family reported him missing. It had \"ruled out that Abbas had been detained for questioning or was wanted by police in any criminal manner . \"The father of the missing man stated that his son suffered from psychological problems, sometimes going to the beaches in the area and requiring assistance in returning home,\" it added. Tensions have remained high in the tiny kingdom after Shiite-led mass demonstrations which rocked Bahrain last February and March were violently crushed by government forces using live ammunition and heavy-handed tactics. A special commission appointed to probe the crackdown on anti-government protests published a report in November denouncing the \"excessive and unjustified use of force\" by the authorities. Bahrain\'s Shiite community, although a majority in the Sunni-ruled kingdom, has complained of marginalisation.