A seven-year-old boy who was rescued from the water after a mother and daughter drowned off an Essex beach has died in hospital.Musa Ahmed died 'in a state of ease and peace' at the Royal London Hospital last night, his family said.He was airlifted to hospital on July 22 following a 'family day out' at West Mersea Beach where he and five other relatives got into difficulty in the water having been swept away by a 'very strong' tide.His 15-year-old cousin, Sameeha Rahman, and her mother Shelina Rahman, 41, both died at the scene.The family said in a statement: 'We would also like to thank the Royal London Hospital intensive care unit team of doctors and nurses who demonstrated outstanding care and dignity for whilst we have been at the hospital.'We would also like to thank the whole community for their support and prayers.'We would appreciate privacy during this very difficult time.'Musa's father, Shahin Ahmed, said in a post on social media that his son was 'such a unique, happy personality, a sphere of joy'. Detective Chief Inspector Al Pitcher said: 'All our thoughts are with the family and friends of those involved – as has been the case since this incident took place last week. Sameeha Rahman, 15, (pictured with father Dr Mansur Rahman) died alongside her mother when she bravely tried to rescue a young child who had got into difficulty in the water It was revealed the victims in the incident were British-Bangladeshi mother Shelina Rahman (pictured), a teacher in her 40s, and her 15-year-old daughter'Their bravery and strength has been humbling. We continue to build a complete picture of the circumstances which led up to this incident and our work is continuing alongside our partners.'Essex Police previously said officers were called by the ambulance service at 5.35pm on July 22 after reports several people had got into difficulty in the water near Seaview Avenue.The East of England Ambulance Service said one patient was transported by air and three taken by road to hospital after the incident at Sea View Holiday Park.Mr Ahmed released a statement early on Monday in which he called for 'a review of safety measures' at the site.'I strongly agree with the calls from local residents for a review of safety measures at West Mersea Beach, including the provision of additional life–saving equipment and clear warning signage,' he said.'While no action now can undo the pain we are suffering, we hope lessons can be learned to help prevent similar tragedies from happening in the future.'Labour MP Naz Shah, for Bradford West, last week paid a personal tribute to Ms Rahman and her daughter.She told the Daily Mail: 'I'm devastated. They're a lovely, lovely family, I'm absolutely heartbroken for them, it's sent shockwaves through the community.'I just can't believe what's happened. I've spoken to the family, and I just broke down - I've got a 14-year-old myself.'I would just reiterate to people to follow water safety advice. And my thanks to the emergency services [who responded to the incident].' Two police officers on Wednesday night near to the scene where Shelina and Sameeha Rahman died Emergency services at the scene after the incident in West Mersea on Wednesday night