A senior judge has conducted a public court hearing behind closed doors because a key could not be found.
Sir James Munby, the most senior family judge in England and Wales, handed down a Court of Appeal ruling at the public hearing at the Royal Courts of Justice.
No lawyers were required to attend the hearing - and no members of the public turned up.
But three reporters aiming to cover the hearing and collect copies of the written ruling were unable to get into the courtroom because the public entrances were locked.
A court official tracked down the journalists within minutes of the hearing ending and provided copies of the ruling.
And Sir James - who has mounted a campaign for greater transparency in family courts and was sitting at the same time as appeal judges were in a nearby court ruling on whether a terrorism trial could be held in secret - later apologised to anyone who had been unable to get into the courtroom.
He said the public hearing had taken place behind closed doors inadvertently.
Court doors are normally unlocked by court ushers.
Staff said no usher had been at today's hearing and a court clerk had been unable to find the key to the doors used by the public.
Union officials who represent court staff said the incident had a serious underside.
Public and Commercial Services union officials said the behind-locked-doors hearing was a consequence of Government cuts in the numbers of court ushers and clerks.
"Cuts across the civil service and our justice system are clearly having a damaging effect," said a union spokesman.
"When the Government cuts staff in our courts it can have very serious consequences for the public's access to justice."