A man has been arrested over racist graffiti daubed on doors at a block of flats.
David Yamba, 10, found "No Blacks" painted on three doors in his block in Salford on 8 February, five days after his family had moved in.
A 54-year-old man has been arrested on suspicion of racially aggravated criminal damage and is being questioned by police.
David's father had earlier criticised police for a slow response.
Greater Manchester Police (GMP) said the family were being supported by officers.
Supt Howard Millington added: "I want to emphasise that we are acutely aware of the strength of public feeling surrounding this incident."
David's father, trainee lawyer Jackson Yamba, said officers did not follow up his initial report until he tweeted the force a week later.
GMP's chief constable apologised for the delay in sending officers to investigate.