Police are requesting information from the public following an incident on New Road, Brighton, on December 22.
Around 12:30pm, officers responded to reports of a man being attacked with a knife.
A man in his 40s suffered a severe hand injury and was hospitalised for treatment.
A 44-year-old Brighton man has been detained on suspicion of grievous bodily harm and released on bail as investigations continue.
Authorities believe there are numerous witnesses yet to come forward and are urging anyone who witnessed the event to contact them.
Witnesses can report information through the police’s online form or by calling 101, quoting reference 581 of 22/12.
