Reddit has rejected a request to hand over the personal details of an alleged music leaker to Atlantic Records.
The record label claims the user uploaded the track Heathens, by band Twenty One Pilots, from Suicide Squad: The Album, months ahead of its planned commercial release.
Atlantic Records started legal action demanding Reddit hand over the user's details and net address.
The website refused, saying the claimant was on a "fishing expedition".
Details of the case were first reported by the news site TorrentFreak.
The unreleased track, on the soundtrack album to the film Suicide Squad, had been issued to:
- a number of workers at Atlantic
- employees at its subsidiary label Fuelled by Ramen
- the two members of Twenty One Pilots
- the band's manager.
All were "contractually obligated and/or under a fiduciary obligation" not to reveal the song's existence, Atlantic said.
The file was initially uploaded to anonymous Slovakian file-hosting service Dropfile.to, before a Reddit user posted the same file on the forum under the name twentyoneheathens on 15 June.
Atlantic attempted to get the files removed from the internet, but conceded it could not prevent their wider distribution.
The individual track was released officially the next day, nearly two months ahead of plan.
The record label then sued, claiming the leak had caused it substantial harm in terms of lost sales.
It demanded Reddit hand over the internet protocol (IP) address and other relevant information to help identify the reported leaker.
Reddit refused, saying Atlantic had not outlined what steps it would take if the IP address was linked to somebody who was not one of its own employees.
For its part, Dropfile says it does not store users' IP addresses and that files expire within 24 hours on its homepage.
A Dropfile representative told the BBC the site had not been contacted by Atlantic at any point.
Suicide Squad: The Album was released on 5 August and sold about 182,000 copies within its first week shooting to number one on the US Billboard 200 chart.
The court's decision is pending.