Burnell Mitchell held over conspiracy to murder and terrorism offences . The 61-year-old Muslim convert is brother of Boney M singer Abdul Hadi Arwani . He was arrested by police investigating the death of Liz Mitchell . Leslie Cooper , 36 , has been charged with the Syrian-national 's murder . A 53-year-old woman was also arrested on suspicion of terrorism offences .
Burnell Mitchell held over conspiracy to murder and terrorism offences . The 61-year-old Muslim convert is brother of Boney M singer Liz Mitchell . He was arrested by police investigating the death of Abdul Hadi Arwani . Leslie Cooper , 36 , has been charged with the Syrian-national 's murder . A 53-year-old woman was also arrested on suspicion of terrorism offences .