A coroner may ask for a police inquiry after discovering that a doctor, called as a witness to a baby's inquest, had been told what to say by a consultant.
Six-month-old Julia Gujdanoca died at Sheffield Children's Hospital after being moved from a critical care unit to make space for new patients.
A verdict of natural causes, contributed to by neglect, was recorded by the city's assistant deputy coroner.
David Urpeth also said some doctors had been "evasive" in their evidence.
Mr Urpeth said at the inquest: "I'm satisfied there is a causal link between the gross failures and Julia's death.
"I'm entirely satisfied that these failures amounted to gross failures to provide basic medical attention."
Mr Urpeth heard how one doctor in the case had admitted she had been told by another witness - a senior consultant - what to say when she gave evidence at the hearing.
The coroner said he was meeting with the chief executive of the hospital before deciding whether to trigger a police investigation into this behaviour.
The hearing at Sheffield's Medico-Legal Centre was told how Julia was transferred out of the hospital's paediatric critical care unit (PCCU) in the middle of the night to make way for other young patients.
She was taken to the regular S1 ward, where her condition deteriorated and nursing staff became increasingly concerned.
The coroner heard how, three-and-half hours after she first became distressed, a decision was taken to transfer her back into intensive care after repeated requests by concerned nursing staff.
But she suffered a cardiac arrest during the transfer and died soon afterwards, on 22 October last year.
Mr Urpeth said his decision to bring in the "neglect" verdict was "a serious finding and not one I have reached lightly".
He said: "The failures here were indeed gross. I am of the opinion the transfer of the patient was wholly inappropriate."
The coroner made a point of saying the nurses on the S1 ward "did all they could possibly do faced with the awful position they found themselves and Julia in".
'Got to truth'
Mr Urpeth made repeated criticism of some of the doctors who gave evidence in the case, each of whom he repeatedly quizzed about whether they believed Julia would have lived if she had been left on the PCCU.
He said: "I have been disappointed with the reluctance of some witnesses to be as helpful as they could have been.
"This court should not have to suffer evasiveness from professional witnesses.
"Nevertheless, I'm satisfied I have now got to the truth."
In a statement, Chris Sharratt, the chief executive of Sheffield Children's NHS Foundation Trust, said changes had been made at the hospital to restrict the movement of patients overnight.
He said the coroner's comments about lack of co-operation by some witnesses would also be investigated.