UKNova has stopped offering BitTorrent links after becoming the latest file-sharing site to be targeted by copyright defenders.
Its administrators said they took the action after receiving a demand from the Federation Against Copyright Theft (Fact).
UKNova had pitched itself as a free catch-up TV and radio service and had asked its members not to add material available for sale elsewhere.
It has been in operation since 2003.
UKNova's use of BitTorrent links meant it did not keep any pirated material on its own servers, but rather provided the means for its members to download and upload material to and from each others' computers.
Fact confirmed it had been in contact with the site, but declined to provide more detail when contacted by the BBC.
Unlike many other file-sharing sites, UKNova did not run adverts on its pages. One of its administrators said it was not run for profit, had survived purely from voluntary donations and nobody involved had been paid.
"Our main concern always was to take an ethical stance and to do no harm to any revenue streams of programme makers or broadcasters," Roger Evans told the BBC.
"To ensure that happened we always had a strict policy that nothing available on DVD or premium TV channels would be available."
Mr Evans said the service had about 30,000 members, including troops in Afghanistan and workers within the television industry.
He said it would continue to offer a forum and chat service, but no new members would be allowed to join for the foreseeable future following the complaint.
"Among the members of Fact are BSkyB and the Premier League and our first step was to take down links to their material," Mr Evans added.
"But Fact said every link was infringing and had to be taken down - which means it was acting on behalf of broadcasters that are not even members of the organisation.
"In nine years of operation we had never received a complaint from any TV channel. We do not believe Fact would have been able to bring a successful prosecution against us - but at this stage we have no money or resources to defend our case in court."
Fact has also been involved in jailing of the owner of Surfthechannel.com - another site that provided links to illegally copied TV programs as well as movies.
Anton Vickerman faces four years in prison after being found guilty of conspiracy to defraud in June for "facilitating" copyright infringement.
He was arrested after Fact teamed up with the Motion Picture Association of America to hire a private investigator who took photographs of Mr Vickerman's computer equipment inside his home after pretending to be interested in buying the property.
Other file-sharing sites to be taken offline in recent months include BitTorrent tracker Demonoid and the digital locker service Megaupload.
In addition the courts have ordered several internet service providers to restrict access to The Pirate Bay and Newzbin.