  The radiative cooling time of the hot gas at the centres of cool cores in
clusters of galaxies drops down to 10 million years and below. The observed
mass cooling rate of such gas is very low, suggesting that AGN feedback is very
tightly balanced or that the soft X-ray emission from cooling is somehow hidden
from view. We use an intrinsic absorption model in which the cooling and
coolest gas are closely interleaved to search for hidden cooling flows in the
Centaurus, Perseus and A1835 clusters of galaxies. We find hidden mass cooling
rates of between 10 to 500 Msunpyr as the cluster mass increases, with the
absorbed emission emerging in the Far Infrared band. Good agreement is found
between the hidden cooling rate and observed FIR luminosity in the Centaurus
Cluster. The limits on the other two clusters allow for considerable hidden
cooling. The implied total mass of cooled gas is much larger than the observed
molecular masses. We discuss its fate including possible further cooling and
collapse into undetected very cold clouds, low mass stars and substellar
objects,
