A former doctor at Great Ormond Street Hospital has been temporarily suspended from the medical register while being investigated over child abuse claims.
Philipp Bonhoeffer, who stopped seeing patients at the London-based hospital in 2009, faces a General Medical Council (GMC) disciplinary hearing.
The Metropolitan Police (Met) said the allegations involved children in Kenya but no arrests had been made.
Dr Bonhoeffer said he strongly denied any impropriety or misconduct.
The GMC has barred the internationally-renowned paediatric cardiologist from practising as a doctor in the UK while its proceedings are ongoing.
He was due to appear before a GMC fitness to practise panel but the case was halted after his lawyers applied for a judicial review which is due to be heard at the High Court on Friday.
His lawyers have objected to the GMC wanting to use hearsay evidence for its case.
The Met said it first received the allegations in September 2008.
A spokesman said: "An investigation commenced and the alleged victims were interviewed in Kenya.
"The investigation concluded in April 2009. No arrest was made as the alleged offences were not prosecutable in the UK for legal reasons.
"Intelligence databases were updated at that time and information shared with relevant agencies as necessary to discharge our duty to safeguard children."
During an initial hearing last year Alyson Leslie, the chair of the GMC panel hearing the case, said: "The issues and alleged misconduct which have led to Dr Bonhoeffer's referral to this panel include concerns of a most serious nature, particularly in the light of his medical speciality which entails regular access to children."
Great Ormond Street Hospital (GOSH) has set up a helpline for parents but said it had no reason to believe that anyone in the hospital had been put at risk.
A GOSH spokeswoman said: "This doctor no longer works for us. He stopped seeing patients at the trust in 2009.
"We have been reassured by the GMC that this hearing is unconnected with his duties at the hospital.
"However, any families seen by him at GOSH who are concerned can call 020 7762 6200."