A man suffered a broken jaw following an assault in East Grinstead early on Christmas morning (25 December).
The victim was struck in the face when walking along London Road around 3am.
A local man has been questioned in connection with the alleged offence and police are keen to speak to anyone who may have seen anything at the time.
Anyone who saw what happened or may have other information about this incident is asked to email 101@sussex.pnn.police.uk or phone 101, quoting serial 179 of 25/12.
Alternatively they can contact the independent charity Crimestoppers without having to leave their name on 0800 555 111 (www.crimestoppers-uk.org)