Jo O’Meara, who was caught up in last year’s Celebrity Big Brother race row, was struck on the head by a glass hurled from a crowd as she performed in a nightclub.
The 29-year-old S Club 7 singer was left with a head wound and had to be helped off stage, according to reports.
The incident happened at Tokyo nightclub West Yorkshire in the UK.
A police spokeswoman said: “A 20-year-old man was arrested on suspicion of assault and remains in police custody.”
The Sun reported that O’Meara was taken to hospital but was later allowed to return to her London home following the reunion tour gig which involved two other bandmates from the original S Club 7 line-up – Bradley McIntosh and Paul Cattermole.
O’Meara told the newspaper: “We were all having a great time until the incident and would like to apologise to fans that our set was cut short.”
Last year’s Celebrity Big Brother race storm attracted the most complaints in Ofcom’s history.
The media watchdog said that about 45,000 complaints were received over the furore surrounding treatment of Bollywood star Shilpa Shetty by O’Meara, Jade Goody and Danielle Lloyd during the Channel 4 programme.