The incident happened at 3:30 p.m. on July 18. The suspect, who said he was 17, shot the victim and his friends off Bournemouth before starting a conversation, Dorset detectives said.
He then allegedly dragged the girl into deeper water and attacked her.
The suspect told the girl he was on his way to Birmingham and may have been of Pakistani descent.
Police are calling on girls who exchanged Snapchat messages with young Asian men on the beach to come forward.
The suspect is described as lean and muscular. He would have worn black or gray swim shorts.
Detective Inspector Wayne Seymour said: “As part of our investigation, we have obtained forensic evidence which means that we will be able to eliminate anyone who was not involved.
“We have also received a number of reports of young Asian men approaching bathers on the date of the incident.
“I urge anyone who has exchanged Snapchat messages with someone who approached them on the beach that day to please contact us.”
Officers will increase seaside patrols over the summer.
READ MORE: Scheming drug addict stole £ 4,600 from pensioner who paid her for sex
–
