Police said detectives are ‘investigating a serious assault involving a glass bottle’.
A police spokesperson said: “Just after midnight on Tuesday (1 July), a fight broke out on a train between Brighton and Haywards Heath. During the fight, a person was seen threatening a man with a glass bottle. They then broke the glass bottle and stabbed him in the chest with it.
“Officers attended Haywards Heath, alongside paramedics, and two people were taken to hospital for treatment for non-life-threatening injuries. A man was arrested on suspicion of grievous bodily harm but was later released without charge, while another man was arrested on suspicion of affray.
“Officers believe the woman in the CCTV image may have information which could help their investigation. Anyone who recognises her is asked to contact BTP by texting 61016 or by calling 0800 40 50 40, quoting reference 17 of 1 July 2025. You can also contact Crimestoppers anonymously on 0800 555 111.”

1. CCTV
Officers believe the woman in this CCTV image may have information that could help their investigation. Photo: British Transport Police Photo: British Transport Police