A High Court judge is considering whether a boy at the centre of a treatment dispute after suffering brain damage should undergo further tests.
Specialists treating Archie Battersbee, 12, at the Royal London Hospital in Whitechapel, east London, think it "highly likely" he is dead and say life support treatment should end.
Archie's parents, Hollie Dance and Paul Battersbee, from Southend, disagree.
The hospital's legal team said it was prepared to carry out more tests.
Justice Arbuthnot, who is overseeing Archie's case at private hearings in the Family Division of the High Court in London, indicated she would make a decision about whether more tests were needed at a further hearing on Friday.
A barrister from Barts Health NHS Trust, which runs the Royal London Hospital, told the court specialists thought Archie had been "extensively investigated".
But she added they were prepared to carry out further tests for "the sake of no stone being left unturned".
The judge also heard from a specialist who said he thought scans showed that Archie had suffered "irretrievable" brain damage.
Two others said they thought tests showed he was "brain-stem dead".
Archie's family have asked the judge to visit him in hospital before deciding whether treatment should end.
Archie suffered brain damage in an incident at home and was found unconscious on 7 April.
His mother Hollie Dance, 46, said she would "never give up fighting" to keep her son alive.
His parents are against removing life support and want more time to see if he will improve.
The final hearing will take place on 6 and 7 June.