A Vienna lawyer says he was involved in the video sting that brought down far-right leader Heinz-Christian Strache.
The lawyer - named by Germany's Bild newspaper as Ramin Mirfakhrai - said it was a "civil society-driven project in which investigative-journalistic approaches were taken".
However the statement does not reveal who was ultimately behind the sting operation, or who paid for it.
The scandal has led to the collapse of Austria's coalition government.
Chancellor Sebastian Kurz is facing a no-confidence vote in parliament on Monday.
If he survives he will try to stay on until elections, probably in September.
What does the lawyer say?
The statement said that "the reactions of the politicians involved" had developed "a momentum of their own".
It said the considerations behind the publication were "democratic-political and legal".
Austrian media reports say that the lawyer is one of three people facing legal proceedings brought by Mr Strache.
Johann Gudenus, a Freedom Party politician who also appears in the video, has told the media that the Vienna lawyer was the person who established the contacts between him and the woman who posed as a Russian oligarch's niece.
What has the political fallout been?
Mr Strache stood down as vice-chancellor hours after the video emerged.
His Freedom Party (FPÖ) then quit the coalition after President Alexander Van der Bellen fired FPÖ Interior Minister Herbert Kickl.
Mr Kurz, from the centre-right People's Party (ÖVP), has replaced far-right ministers with technocrats.
What is in the video?
The scandal is widely being labelled "Ibiza-gate", after the Spanish island where the video was recorded. It was made just weeks before the election which saw both the FPÖ and Chancellor Kurz's People's Party perform well.
In the footage, released earlier this month by German media, Mr Strache can be seen relaxing and drinking for hours at a villa with Mr Gudenus, while they meet the supposed Russian oligarch's niece.
During the conversation, Mr Strache appears to propose offering her public contracts if she buys a large stake in the Austrian newspaper Kronen Zeitung - and compels it to support the FPÖ.
He is heard suggesting that a number of journalists would have to be "pushed" from the newspaper, and that he wants to "build a media landscape like [Viktor] Orban" - referring to Hungary's nationalist leader.