Fuel pump whirr

Since this week, I am getting another unusual event with the R1. Normally as soon as you turn the ignition key, you hear two distinctive 'whee - whee' sounds, which should be the high pressure fuel pump (and maybe also the low pressure fuel if there is one) because the whee sound has two different pitches. Well, I hear the first whee sound, but the second is a 'CLUNK' noise. It does not affect the operation of the bike though. Just don't know what it is.