The MPAA (through their UK minions, FACT, a "private commercial organisation, representing the interests of the audio-visual industry") did some investigating to find out who the operator of SurfTheChannel.com was. After various undercover meetings, fake deals and that sort of thing, they were able to identify the operators as a UK-based couple. Then they set the police on them.
The police turned up, with FACT people, and arrested the couple, seizing a load of evidence, and a FACT specialist was able to copy a load of data from the computers (and may have done so illegally). While in custody the couple were interviewed with FACT people present, FACT were able to examine the evidence, and eventually most of it was handed over to them for analysis.
Eventually, the couple were released and the CPS (who decide whether or not to bring prosecutions) decided not to charge them. The police then handed the rest of the evidence over to FACT who wanted it so they could run a private prosecution. The couple sued the police and FACT to get their stuff back (after their direct requests were refused). These facts all come from the resulting case (Scopelight Ltd & Ors v Chief of Police for Northumbria & FACT) which FACT won on appeal.
The initial arrests were in August 2008, the CPS gave up in December 2008, FACT filed their private prosecution in February 2009 and that appeal was ruled on in November 2009. This new information has come to light because that private prosecution is currently being heard in Newcastle Crown Court.
The other major fact that emerged was that the US programmer who worked on the site was arrested by US authorities, but managed to get out of being convicted for his part in exchange for agreeing to testify in the UK case. So the US let an alleged criminal go so he could help a private, UK-based company win a private prosecution in the UK.