Jelster, I think this was the 'oil-wicking' issue which seemed more prevalent on the 2010 - 2012 R56s.
It was a known issue at the time (first noticed on NAM) and my 2012 N18 MCS was duly fixed after I checked and spotted a small leak at the back of the sump, which I reported to my local dealer.
For me MINI dismantled the sump and fitted new gasket(s?) and a modified solenoid or sensor (I think) along with extra sealant around the solenoid/sump area.
I gather the wiring loom attached to this unit needs replacing, too, since it becomes saturated with oil which 'wicks' its way upwards towards the more central part of the loom; so IMO it might be worth bringing this part of the fix to your indy's attention, too.
Hope this helps.