Ronan Farrow’s investigation into Harvey Weinstein’s long history of alleged sexual misconduct was in NBC’s hands as recently as August, according to multiple sources both inside and outside the network. By then, Farrow, an NBC contributor and investigative reporter, had already obtained damning audio of an encounter Weinstein had with a woman, in which Weinstein admits to having groped her, sources told HuffPost.

Instead, Farrow’s story — and the audio, from a 2015 New York Police Department sting — appeared Tuesday on the website of The New Yorker. Sources told HuffPost that NBC had concerns related to the story’s sourcing and cleared Farrow to take it to The New Yorker.

It’s not clear what those concerns were. In The New Yorker story, several women spoke on the record about their encounters with Weinstein. Among them were Oscar-winning actress Mira Sorvino and filmmaker Asia Argento, the latter of whom said Weinstein raped her.