clause 2.3b of the competition rules
Just to make things clear, this isn't about eligibility to enter and compete in the competition; it's just about eligibility to be awarded a prize.
Eligibility to enter and compete is covered by Section 2 of the 'Official Rules' which is headed "Eligibility to take part in Data Challenges" and the only restrictions to entry are:
2.1 Data Challenges are open to individuals aged 18 and over. Entries made by or on behalf of corporate entities will not be accepted.
2.2 Officers, directors, employees and their immediate families of the Sponsoring Agencies, BAE Systems, Capgemini UK PLC, Roke Manor Research Limited and their respective group companies, contractors and agents may not participate in Data Challenges.
However, clauses 2.3 & 2.4 of the competition rules do not refer to eligibility to enter and compete but just address exclusions of payment:
2.3 No payment shall be made (whether directly or via a third party/country) to:
2.4 If UK Government is not (or its authorised representative is not) reasonably satisfied as to the potential recipient's identity, no payment shall be made to that person.
And it is sub-clause 2.3b that refers to "a score of 37 or less according to Transparency International's Corruption Perceptions Index 2014"
I find it a bit puzzling to allow someone to enter but then specifically exclude them from being awarded a prize, should they win.