A 22-year-old man was arrested on suspicion of an assault on two teenagers and a policeman at Wimbledon station on Saturday night.
Police were called to the scene just before 11pm and arrested the man on suspicion of being drunk and disorderly, sexual assault, wounding and assaulting a policeman.
The teenage couple, both 16-years-old, were on a night out when the alleged assault took place.
The suspect has been bailed until February 25 while police investigate.
Anyone who witnessed the incident should contact British Transport Police on 0800 405040, quoting crime reference number 594, January 25 2014.
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