  We study a double quantum dot (DQD) coupled to a strongly biased quantum
point contact (QPC), each embedded in independent electric circuits. For weak
interdot tunnelling we observe a finite current flowing through the unbiased
Coulomb blockaded DQD in response to a strong bias on the QPC. The direction of
the current through the DQD is determined by the relative detuning of the
energy levels of the two quantum dots. The results are interpreted in terms of
a quantum ratchet phenomenon in a DQD energized by a nearby QPC.
