Wreckage from a plane carrying Cardiff City footballer Emiliano Sala has been discovered in the English Channel.
The Piper Malibu N264DB was lost on 21 January on its way from Nantes, France, to Cardiff, with the Argentine striker and pilot David Ibbotson on board.
David Mearns, who led a privately-funded search for the aircraft, said it was located off Guernsey on Sunday.
He said: "All I will say is that there is a substantial amount of wreckage on the seabed."
Speaking on Radio 4's Today programme on Monday, Mr Mearns said: "We located the wreckage of the plane on the seabed at a depth of about 63m within the first couple of hours [of searching]."
He said the plane was identified by sonar, before a submersible with cameras was sent underwater and was able to confirm it was the plane.
"They saw the registration number and the biggest surprise is that most of the plane is there," he added.
Mr Mearns's private search has now been stood down and the Air Accidents Investigation Branch (AAIB) is at the site working to recover the plane.
He said further investigations by the AAIB would be conducted over the next two days in order to determine how it will attempt a recovery operation.
In a series of tweets on Sunday, marine scientist Mr Mearns said: "The families of Emiliano Sala and David Ibbotson have been notified by police."
He added: "Our sole thoughts are with the families and friends of Emiliano and David."
Wreckage of the plane carrying Emiliano Sala and piloted by David Ibbotson was located early this morning by the FPV MORVEN. As agreed with the AAIB they moved the GEO OCEAN III over the position we provided them to visually identify the plane by ROV. #EmilianoSala— David Mearns (@davidlmearns) February 3, 2019
Speaking to Argentinian broadcaster Cronica TV, Sala's father Horacio said: "I cannot believe it. This is a dream. A bad dream. I am desperate."
Mr Mearns said he was in contact with the Sala family after the wreckage was located and said they "desperately want that plane to be recovered. They feel that is the pathway for them to get the answers that they need to have".
He added he was compelled to help to search for the plane after seeing an emotional plea by Sala's sister Romina.
"I just felt that girl needed help and that's why I offered my assistance," he said.
"I am a football fan. Cardiff is not my city, but I follow football. I felt very badly for her, I wanted to help. I just happen to be a person with this experience and skill and I could do that.
"To add to it this was a man in the prime of his life. It is just so tremendously sad."
Cardiff had signed Sala for a club record of £15m and he was due to start training last month.
The 28-year-old striker and Mr Ibbotson, 59, from Crowle, North Lincolnshire, were travelling from Nantes, where he had previously played, when the flight lost contact with air traffic controllers.
An official search operation was called off on 24 January after Guernsey's harbour master said the chances of survival were "extremely remote".
Cushions believed to be from the plane were found on a beach near Surtainville, on France's Cotentin Peninsula, last week.
There were emotional tributes to the footballer as Cardiff played their first home game since the disappearance on Saturday.
The club's manager, Neil Warnock, said he felt Sala was "with" his team as they beat Bournemouth 2-0 in the Premier League.
An online appeal had raised £324,000 (371,000 euros) for the private search, which began on Sunday.
Working jointly with the AAIB, Mr Mearns's ship and another search vessel, the Geo Ocean III, began combing a four square mile area of the channel, 24 nautical miles north of Guernsey.
The AAIB ship has remained at the site where the missing Piper plane was located, to deploy an underwater search vehicle to make a visual confirmation.
A recovery operation will then begin.
Former air crash investigator Tony Cable told BBC Breakfast on Monday that any examination of the wreckage after it is recovered would take "considerable time".
"Certainly the damage can tell you the sort of altitude and vertical speed, horizontal speed that it hit the water."
He added that there may also be signs of anything that was not working properly.
"The difficulty is if you don't have signs of problems before the crash, you're left looking at possible reasons then which are not a failure of the aircraft. The absence of any problem leaves you somewhat in the realm of speculation."
Officials at the AAIB said they expected to give an update on the operation on Monday morning.