A man in his 20s sustained a serious injury to the head at the China White pop-up night club at Henley Regatta on Saturday night.
A witness who was working in the VIP area of the club said she saw the incident with a smashed bottle being thrown after a fight broke out.
Police were called at around 10pm and the man was taken in an ambulance to the Royal Berkshire Hospital with a bleeding head. The man suffered a fractured skull and black eye but has since been discharged.
A spokesperson for said, “An investigation is ongoing and anyone with information is asked to call 101 or make a report online quoting reference 43230291325.”