An inquest has heard that two youngsters died from drowning after a “suggestion” that they got into difficulty by getting caught in a riptide in the sea off Bournemouth beach.

Joe Abbess, 17, from Southampton, and Sunnah Khan, 12, from Buckinghamshire, were rescued from the sea during the incident on Wednesday, but both died in hospital.

In a hearing to open the inquest proceedings at Bournemouth Town Hall, Dorset coroner’s officer Nicola Muller said that post mortem examinations carried out by Home Office pathologist Basil Purdue showed the cause of their deaths was drowning.

She said that Joe, a trainee chef, was taken to the Royal Bournemouth Hospital where he was pronounced dead, and Sunnah was taken to Poole General Hospital.

She said that Joe was identified by Detective Constable Hannah Webster by a photograph provided by his family, and Sunnah was identified by her father at the hospital.

Describing the incident, Ms Muller said: “The brief circumstances are that emergency services were contacted by members of the public following swimmers had come into difficulty in the water, following suggestion they had been caught in a riptide.”

Rachael Griffin, senior coroner for Dorset, said: “I understand there is an ongoing police investigation, despite that, I have already submitted the appropriate paperwork and released both Joe’s and Sunnah’s bodies for the purposes of their funerals.

“In relation to that ongoing police investigation, I am unable to make any progress in my inquiries.

“It’s very important people do not speculate on the circumstances surrounding Joe and Sunnah’s deaths and allow the police investigation to proceed, which will allow my investigation to proceed.

“I would like to take this opportunity to offer my sincere condolences to Joe and Sunnah’s families, my thoughts are very much with them at this difficult time following this tragedy.

“My thoughts are also with those who attended or witnessed the traumatic events.”

It's very important people do not speculate on the circumstances surrounding Joe and Sunnah's deaths and allow the police investigation to proceed, which will allow my investigation to proceed

She added: “I wish to take this opportunity to remind all those who enter the sea or open water to be aware of the powers of the water and the risks of swimming in open water.

“It’s important they are aware of how to respond when problems arise and urge people to follow guidance from public agencies such as the RNLI.”

Ms Griffin adjourned the hearing until a pre-inquest review to be held on September 18.

Neither of the families of the two deceased were present at the short hearing.

Conservative MP Tobias Ellwood has expressed concern about a lack of clarity from local police officers about the incident, which he said had led to “wild speculation on social media”.

“We do need to understand, learn lessons from this, provide clarity early on, just so people can have an assurance of mind as to what roughly happened,” he told BBC Radio 4’s Today programme.

The Bournemouth East MP said: “Certainly anybody would not want to impede or prejudice the investigation.

“But if the absence of any comprehensive statement becomes standard, I can see who, speaking on a wider picture and security level, those who wish us harm could leverage the void by misleading messaging.”

But David Sidwick, the Conservative police and crime commissioner for Dorset, defended the police’s handling of the “complex” case.

Dorset Police have said that the beach was extremely busy but that neither of the deceased young people or anyone else pulled from the sea at the time of the incident was involved in any collision or contact with any vessel in the water.

A man in his 40s, who was “on the water” at the time, was arrested on suspicion of manslaughter, and was released under investigation on Thursday.

The Dorset Belle sightseeing boat was impounded by Dorset Police after the incident.

Detective Chief Superintendent Neil Corrigan said: “We continue to keep an open mind around the circumstances that have led to the tragic death of two young people in the water off the beach.

“Our thoughts remain with the families of those young people.

“As with any investigation of this nature, we have to look at all factors connected to the state of the water.

“One of those lines of inquiry has involved the pleasure boat, which was in the area at the time of the incident. These inquiries also include examining wind, other weather and general coastal conditions at the time.

“We are working with experts from partner agencies to understand all of the factors and this will take time to establish.”

Joe Abbess’s family paid tribute in a statement saying: “We are heartbroken and devastated at the death of our Joe. He was a wonderful son and brother who is sadly missed.

“His family and friends will always love him and we are incredibly proud of the fabulous young man he was. He was kind and generous, loving and caring, hardworking and funny.

“Joe was a talented trainee chef, with a bright future ahead of him.

“We were privileged to have him in our lives for 17 years and we are so sorry he will never fulfil his dreams and ambitions.

“He was enjoying a day at the beach on Wednesday and we would like to thank his friends and all of the emergency services who helped him, when this tragedy unfolded.”

Sunnah grew in confidence over her first 10 months at Bourne End. She developed a bold and happy personality which resonated throughout the school community

A spokesperson for Bourne End Academy said: “It is with great sadness that we can confirm that one of our students, Sunnah Khan, died during the half-term break.

“As a student, Sunnah grew in confidence over her first 10 months at Bourne End. She developed a bold and happy personality which resonated throughout the school community.

“Her energetic character and fierce sense of loyalty meant that she had built strong and positive relationships with her peers and teachers. She will be enormously missed.”

“Our deepest condolences are with the family and their friends during this difficult time and in due course we will share details of a fitting memorial for Sunnah.”