Iain Overton confirmed today that he has resigned as editor of the Bureau of Investigative Journalism in the wake of its involvement in the Newsnight programme which broadcast allegations linking a senior Tory to child abuse.
Overton had tweeted before the start of the programme that Newsnight would feature an item, which the BIJ worked on, about a "senior political figure" who is a paedophile.
His message - "If it all goes well we've got a Newsnight out tonight about a very senior political figure who is a paedophile" - was retweeted 1,574 times.
Although the programme did not name the politician, it led to speculation on the internet, wrongly implicating former Treasury minister Lord McAlpine.
A message on Overton's Twitter page said: "Iain Overton has resigned as editor of the Bureau."
The organisation issued a statement saying that the Newsnight story had been "strictly contrary to the fundamental principles and standards of the Bureau".
The statement, from chairman James Lee, issued on behalf of the trustees, said: "Iain Overton has resigned his appointment as editor of the Bureau of Investigative Journalism.
"Deputy editor Rachel Oldroyd will assume responsibilities for editorial control of the Bureau. An appointment of an interim editor is likely to be announced in the near term."
The statement added: "An inquiry to establish the role of the Bureau in the story is in urgent progress. An interim report will be issued as soon as possible.
"Trustees reaffirm the Bureau's commitment to fact-based, non-sensational investigation in the public interest.
"Any role by the Bureau or its officers in this story was strictly contrary to the fundamental principles and standards of the Bureau."