UPDATE: Max Milligan, the brother of a man killed in a horrific speedboat incident in Padstow yesterday has paid tribute to an "extremely loving husband, father son and brother", that "doted on his family"

Nicholas Milligan, a senior exec with BSkyB, and his eight-year-old daughter both died in the incident.

His brother Max said that Nick and his daughter "died in their favourite place," which offered the family a "glimmer of light."

“Nick, or Nicko as he was known to us, was an extremely loving father and husband, son and brother who doted on his family," Max said.

“As children and teenagers we spent many summers and New Years’ Eves at New Polzeath here in Cornwall, and a few years ago he built his dream house above Daymer Bay. 

"That he and my delightful niece died in their favourite place at the end of a gloriously sunny bank holiday weekend provides us with a tiny glimmer of light.

“I would like to thank Devon and Cornwall Police and all the staff at Derriford Hospital who have been incredible."

Nick's two girls aged 10 and 12 are reported to have minor injuries and are recovering well. 

There are no further updates on his 39-year-old wife and theirfour-year-old boy. The police said they suffered "potentially life changing" injuries.

An investigation is underway on behalf of the coroner. It is a joint investigation from the police and the Marine Accident Investigation Branch (MAIB), with assistance from the Maritime and Coastguard Agency.

Anyone with any information about the accident can contact the police on 101 quoting log number 603 of 05/05/13.

A key focus of the investigation will be whether a "kill cord" being used on the boat. These stop the engine if the driver moves away from the controls or falls out of the boat.

The police have again paid tribute to the men who helped as the incident unfolded, saying if people had not come to the assistance of the family, the death toll would "undoubtedly" have been higher.

Twenty-five police staff are working on the investigation into the deaths.

UPDATE: Formal identification has now taken place on the 51-year-old man and he can be named as Nicholas Milligan, aged 51 and from Wandsworth - a senior BSkyB executive.

Mr Milligan was managing director at Sky Media since 2004. In a statement on its website, Sky said:

"Everyone at Sky is deeply shocked and saddened to learn of the tragic accident involving the Milligan family.

"Nick has been a great friend and colleague for many years and his loss will be felt across our company and the industry.

"Our very deepest sympathies are with his family at this time."

UPDATE: Formal identification has not yet taken place on the eight-year-old girl, reported to be his daughter Emily.

Detective Superintendent Jim Colwell said: "Our thoughts are with the family and friends who are affected by this tragic incident. 

"I'd like to thank the members of the public who assisted with the rescue of the individuals in the water yesterday and all of the emergency services for safely and swiftly moving the casualties to Derriford.

"Everyone's assistance undoubtedly saved lives."

Eyewitness Maria Chase said: "We were down in Padstow today and saw the tragedy and saw a hero who saved more lives by jumping on to an out-of-control speedboat from another boat."

In footage recorded by a witness and shown on the BBC, the speedboat is seen going around in circles before waterskiing instructor Charlie Toogood intervenes.

The family were in Cornwall for the Bank Holiday weekend when the accident happened in the Camel Estuary near Padstow shortly before 4pm.

The popular harbour area was bristling with people enjoying the sunshine who watched the accident unfold just half a mile offshore.

UPDATE: A waterskiing instructor has been hailed as a hero after a speedboat accident which killed a man and his daughter and left four other members of the family seriously injured.

Charlie Toogood, who runs Camel Ski School in nearby Rock, leapt into the speedboat to turn off its engine and stop it from causing further harm, according to reports.

Watch the video and BBC news report here:

UPDATE: Safety plea after speedboat deaths.

Rob Atkinson, Padstow harbour master, has called for speed boats owners to ensure they are fitted with a "kill cord".

These stop the engine if the driver moves away from the controls or falls out of the boat.

He told Sky News while he could not  talk about this incident as the the Marine Accident Investigation Branch would determine "exactly what happened".

He said: "But as a general, with these boats, there's a safety device fitted called a kill cord. Basically one end of the kill cord has to be plugged into the boat's controls, to make the engine operate.

"That is joined by a cord, to the person in control of the boat.

"If the person in control of the boat goes out of the boat for any reason, I am not sure how it happened in this case, that cord is pulled out of the boat's control, the engine stops instantly.

"I can't comment on this, this speculation, but as a general plea to everyone out there who operates this sort of boat, please, please, please, when you have a boat fitted with a kill cord, make sure the kill cord is operating correctly and make sure it is attached to you because if you go out of the boat, it will stop the engine and it will prevent tragedies like this happening."

ORIGINAL: A 51-year-old man and his eight-year-old daughter have died after being struck by an out of control speedboat in waters off the coast of Padstow.

An investigation has been launched into the crash in the Camel Estuary, off Padstow.

The man's 39-year-old wife Victoria, four-year-old son, Kit, and two daughters Amber (12) and Olivia (10) have been airlifted to Derriford Hospital with serious leg injuries following the collision, which happened in the Camel Estuary on Sunday afternoon.

Emergency services were initially called to the scene after unconfirmed reports that a boat had hit kayakers.

A spokeswoman for the Maritime and Coastguard Agency said: "Falmouth Coastguard was first called at 3.50pm when there were reports that six people had been thrown off a speedboat, and that the speedboat was out of control for a short time."

Lifeboats and search and rescue helicopters from RNAS Culdrose and RMB Chivenor were called to the scene, and Devon and Cornwall Police cordoned off part of the harbour.

The boat has been recovered and the Marine Action Investigation Branch will now examine it to ensure there were "no factors to do with the vessel itself" which could have caused the incident."

Talking to the BBC, eyewitness to the crash, Simon Lewins said that the boat suddenly turned right, "depositing" people into the sea.

"It kept going off in ever decreasing circles. The screams coming from the people in the water were pretty bad."