The arrest comes after police released a CCTV image and appealed for help to identify a man wanted in connection with the incident on October 27 last year.
Detectives said the 17-year-old victim and her friend were approached by two men while shopping in Westfield in Shepherd’s Bush before they were split up and the teenager was attacked.
A Met Police spokesman said: “After being questioned at a London police station, the man arrested was released on bail pending further enquiries.
“Investigators are no longer appealing for help to identify the man in the CCTV image released on Thursday, May 4.
“Detectives from the Met’s Sexual Offences, Exploitation and Child Abuse Command continue to deal with the incident."
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