A father and daughter were killed and four other members of their family seriously injured when their speedboat ran out of control yesterday.

The group, including a four-year-old boy, were thrown from the boat when it flipped over.

Hundreds of holidaymakers who had been enjoying the Bank Holiday sunshine on the Camel Estuary near Padstow watched in horror as the boat raced round in circles, its propeller slashing the helpless victims and turning the water ‘red with blood’.

Last night Devon and Cornwall police confirmed that the two who died were a 51-year-old man and his daughter aged eight. Detective Sergeant James Colwell said: ‘The information is suggesting at the moment that they are not local to the area and are here on holiday, renting a holiday home. Unfortunately the family members that were taken to hospital do have life-changing injuries.’

The survivors were flown to Derriford hospital in Plymouth. They were a 39-year-old woman, a four-year-old boy and two girls aged 10 and 12.

Emergency services were scrambled after they received a large number of calls from members of the public who had been standing on the packed harbourside when they saw the 3.50pm yesterday afternoon.

Three RNLI lifeboats were sent to the scene as well as search and rescue helicopters from RNAS Culdrose and RMB Chievenor.