Police are appealing for a man who tried to prevent an alleged assault in Alfreton to come forward to help them with their inquiries.
At around 2am on Sunday, 9th October a man and his partner were having a heated argument on Grange Street.
An alleged assault took place and a passer-by intervened.
Police were called and a 24-year-old man was arrested on suspicion of assault.
Officers would like to speak to the man who intervened to help them with their inquiries.
If you are the witness or have any information about this incident call Derbyshire police on the new non-emergency number 101 or Crimestoppers anonymously on 0800 555 111.