Hi Mummy2Two, thank you for your concern. I have an African friend who lives in the same block, she has been supportive and encouraged me to report him to the police. He has since been evicted by the lettings agent (in June), but he is so full of vengence that he returned last night at 1am and continuously rang our buzzer via the intercom.
Yes I generally feel I cannot approach the other neighbours. One elderly neighbour actually made the situation worse by showing him support which fuelled his harassment. I feel that those who turn a blind eye to racism or quietly support it are a big part of the problem.