http://www.bailii.org/ew/cases/EWHC/Comm/2010/1900.html

Where an applicant was seeking pre-action disclosure under CPR 31.16 in order to ascertain whether to bring a claim or not, the applicant was not required to establish that he had a case with a “real prospect of success”. However the applicant did have to show a prima facie case which was more than merely speculative.