by A 12-year-old girl and a 17-year-old boy who died after being pulled from the sea off Bournemouth beach were not hit by any vessels, police have said.
Officers released more information regarding what happened on Wednesday when 10 swimmers got into difficulty.
A man in his 40s arrested on suspicion of manslaughter has been released under investigation.
Dorset Police said there was no contact with a jet ski or boat and no-one jumped from the pier.
The force stressed investigations were still in the early stages and it was only releasing certain details to address speculation. What exactly happened is still unclear.
Officers said members of the public rushed to help the 10 swimmers struggling in the water.
The girl and boy, from Buckinghamshire and Southampton respectively, sustained critical injuries and died later in hospital.
Police said they were from separate groups visiting the beach and the arrested man was not known to them.
The eight other people were rescued and treated on the beach.
Police confirmed on Thursday the arrested man was “on the water” at the time of the incident.
In a statement Dorset Police said: “Following initial enquiries, a man aged in his 40s who was on the water at the time was arrested on suspicion of manslaughter. He has now been released under investigation while enquiries continue.”
Emergency services were called to the beach off Bournemouth Pier, which was packed with people on half-term holidays, at 16:32 BST.
In an earlier statement, Dorset Police said: “Early investigation indicates that there was no physical contact between a vessel and any swimmers at the time of the incident.”
‘Crowded sea’
Speaking during a later press conference, Assistant Chief Constable Rachel Farrell thanked members of the public who helped people in trouble in the water, as well as beachgoers who “quickly moved and let the emergency services do their jobs”.
Dr Rob Rosa was on the beach and helped emergency service crews trying to resuscitate the 12-year-old girl.
In a post on social media, he said: “Many of the lifeguards on the beach were teenagers themselves and despite their training would not have encountered such a scene, let alone having to resuscitate two children simultaneously whilst actively searching for others in a crowded sea.
“These young lifeguards did everything asked of them, they didn’t panic, there was no hysteria, they were exceptional and they followed instruction to the letter whilst taking their own initiative.”
Air ambulances landed on the beach, while a lifeguard attended on a jet ski in a bid to rescue those who were in the water.
The coastguard also conducted a search to make sure no other people were missing and said it was “satisfied there are not”.
A section of the beach and the nearby Pier Approach were cleared and a cordon was put in place.
The RNLI is now offering support to the lifeguards who were on the scene.
Tobias Ellwood, the Conservative MP for Bournemouth East, said protocols on the pier could be reviewed after the “terrible tragedy”.
He said Bournemouth prided itself on being a family resort and the incident had taken “everybody by shock”.
Leader of Bournemouth, Christchurch and Poole Council, Vikki Slade, told members of the press making sure the beach is safe would be a “top priority” for the authority.
She said extra staff would be on at the scene this weekend and lifeboat support from the RNLI would be visible.
When asked about the protocols in place for water safety, she said the team “is always looking at these issues, but today isn’t the day for that”.
Dorset Police is appealing for witnesses to come forward and has said further information will be released “as the investigation progresses”.
The Marine Accident Investigation Branch and the Maritime and Coastguard Agency are also involved in the investigation.
