  We describe the dynamical evolution of a unique type of dark star cluster
model in which the majority of the cluster mass at Hubble time is dominated by
an intermediate-mass black hole (IMBH). We analyzed results from about 2000
star cluster models (Survey Database I) simulated using the Monte-Carlo code
MOCCA and identified these dark star cluster models. Taking one of these
models, we apply the method of simulating realistic "mock observations" by
utilizing the COCOA and SISCO codes to obtain the photometric and kinematic
observational properties of the dark star cluster model at 12 Gyr. We find that
the perplexing Galactic globular cluster NGC 6535 closely matches the
observational photometric and kinematic properties of the dark star cluster
model presented in this paper. Based on our analysis and currently observed
properties of NGC 6535, we suggest that this globular cluster could potentially
harbour an IMBH. If it exists, the presence of this IMBH can be detected
robustly with proposed kinematic observations of NGC 6535.
