Hungarian prosecutors have opened an investigation into whether police can be held criminally responsible for abuse over the death of a Syrian migrant who drowned in the Tisza river as he was trying to cross into Hungary from Serbia this month. Farhan al-Hwaish, 22, drowned in a branch of the river on June 1 when a group of migrants tried to cross into Hungary with the help of human traffickers. Police found his body two days later. His brother, who crossed with him, says he drowned after Hungarian police guarding the border on the river bank threw objects at them, sprayed them with gas and unleashed attack dogs to prevent them from climbing out of the water.