It's Rudd-ywell official: no funding from the Saudis (and no report either):
http://www.bbc.co.uk/news/uk-40581819
Most money comes from 'small, anonymous public donations' mainly from 'UK-based individuals'. Solution: public awareness campaigns, raising awareness in the financial services sector, increasing regulatory oversight...
Oh, and 'raising issues of concern, supported by evidence, with specific countries'.
That'll show 'em.