According to reports the homes in Middlesbrough are owned by Jomast, a subcontractor of services giant G4S, and were painted red so employees knew which were occupied by asylum seekers.
Would-be refugees from Syria and eastern Europe told an investigation by The Times they had been targeted as a result.
One woman claimed yobs shouted: “Fuck you dirty women. Get out of our country.” Another said a National Front logo was carved in their red front door.
G4S and Jomast have strenuously denied the claim that the colour was used deliberately, but recognised that “the majority” of doors in the housing stock were red.
Immigration minister James Brokenshire said: “I am deeply concerned by this issue and have commissioned Home Office officials to conduct an urgent audit of asylum seeker housing in the North East.
“I expect the highest standards from our contractors. If we find any evidence of discrimination it will be dealt with immediately as any such behaviour will not be tolerated.”
According to The Times, of the 168 Jomast houses it identified in two of Middlesbrough’s most deprived areas, 155 had red front doors.