A campaigner said judicial heads should examine a family court case in which a five-year-old girl from an English-speaking Christian family was placed with mixed-race foster parents and learn lessons.
Former Liberal Democrat MP John Hemming said the case showed that a drive for family court transparency was not working.
He raised concerns after security staff at the East London Family Court in Canary Wharf told journalists that they were not allowed into the building - let alone into hearings.
Reporters said they were forced to wait outside for 90 minutes on Wednesday after being refused access to the court building by security staff.
Journalists said they were allowed into the building after a senior judge intervened. A Ministry of Justice spokesman later apologised.
"Sir James Munby, the most senior family court judge in the country, has launched a drive for transparency but this case shows that it isn't working," said Mr Hemming, who campaigns for improvements in the family justice system.
"We've had a situation here where journalists have been told that they can't enter a public building, let alone listen to a hearing.
"The East London Family Court must be the most secret court in the country.
"What reporters have been told is completely wrong.
"Of course people can enter public court buildings.
"Members of the public are not allowed into private family court hearings but the rules allow media representatives to sit on any family court case.
"A judge decides what can be reported - and has the power to exclude journalists in some circumstances - but reporters can sit in and listen and perform a vital public watchdog role.
"It is alarming that court staff do not know the rules - although I'm not surprised.
"The picture we see is that the rules are generally followed in the Family Division of the High Court - which is based at the Royal Courts of Justice in London.
"High Court judges and staff regularly see journalists and they know the rules.
"But I don't think the transparency message is filtering through to local family courts up and down the country.
"I think Sir James should look at this case to try to learn lessons."
Mr Hemming said family court listings should also be changed.
"The cases are listed by their numbers," said Mr Hemming.
"How can reporters be expected to find the cases they are looking for? Listing by numbers doesn't make family courts transparent.
"Of course there's a need for children's identities to be protected.
"But, for example, when a council is involved in a care case why can't the name of that council be included on a public listing of the case?"
He added: "The danger is that privacy rules aimed at protecting children can allow public authorities to keep controversial decisions out of the spotlight."
A Ministry of Justice spokesman said: "We apologise for the issues journalists faced accessing East London Family Court.
"We have acted swiftly to remind all staff across the entire London area of the correct processes.
"We recognise the vital part the media play in ensuring justice is seen to be done, and are committed to open justice, and access and transparency across our courts."
Copyright (c) Press Association Ltd. 2017, All Rights Reserved. Picture (c) David Jones / PA Wire.