The judge leading the Leveson Inquiry into media standards has suggested the planned second part of his probe - into specific allegations of wrongdoing at the News of the World - may not go ahead.
The lengthy delay caused by the need to await the conclusion of police investigations and possible trials means that it will be "very many months, if not longer" before the second part of the inquiry can begin, said Lord Justice Leveson.
Although he did not rule out pressing ahead as planned, he suggested that consideration should be given to the value of a second inquiry which would involve "enormous cost" to taxpayers and participants and would "trawl over" material which is many years out of date.
In a ruling published late on Tuesday on the inquiry website, Lord Justice Leveson said he believed it was "in everyone's interests" to allow the first part of his investigation at the Royal Courts of Justice to go "as far as it possibly can" in the hope of answering public concerns about press behaviour.
When Prime Minister David Cameron commissioned the probe in the wake of revelations about phone-hacking at the News of the World in July 2011, he gave Lord Justice Leveson a remit to carry out an inquiry in two parts.
The first, to start immediately, would inquire into the "culture, practices, and ethics" of the media, including contacts and relationships between the press, politicians and police, and make recommendations for a more effective policy and regulatory regime in the future.
Only after the completion of any police investigations or trials would the judge begin the second part of the inquiry, addressing "the extent of unlawful or improper conduct within News International, other newspaper organisations and, as appropriate, other organisations within the media", as well as allegations of corrupt payments to police and complaints about the initial police response to phone-hacking claims.
With police currently investigating a number of individuals and no indication of whether or when any prosecutions may be brought, it is thought likely to be 18 months or longer before the second part of the inquiry can begin.
Lord Justice Leveson stressed that the possibility that the second part of the inquiry may not go ahead has not affected his approach to the first part.
But he added: "It is undeniably a sensible strategic consideration for those who have participated in this inquiry."