* Qatar says BBC crew trespassed on private property
* BBC demands explanation, deplores detention
* Tour arranged to see conditions of migrant workers
DOHA, May 18 (Reuters) - A BBC television team was arrested in Qatar and held for two nights in prison while reporting on living conditions for migrant labourers working on the 2022 World Cup, the broadcaster said on Monday.
The Gulf state had organised a press tour in early May for journalists from Britain, elsewhere in Europe and the Middle East to examine the conditions labourers face, amid global criticism of human rights violations in the Gulf Arab state.