  We apply a matched-filter cluster detection algorithm to the
Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) i-band data for the
Deep-1, Deep-2, Deep-3 and Deep-4 fields covering a total of 4square degrees.
To test the implemented procedure we carry out simulations for assessing the
frequency of noise peaks as well as estimate the recovery efficiency. We
estimate that up to z~0.7 the catalogue is essentially complete for clusters of
richness class R>~1. The recovered redshifts are in general overestimated by
dz=0.1 with a scatter of sigma_dz~0.1, except at redshifts z>~1 where the
estimated redshifts are systematically underestimated. The constructed cluster
candidate catalogue contains 162 detections over an effective area of 3.112
square degrees corresponding to a density of ~52.1 per square degree. The
median estimated redshift of the candidates is z=0.6. The estimated noise
frequency is 16.9+-5.4 detections per square degree. From visual inspection we
identify systems that show a clear concentration of galaxies with similar
colour. These systems have a density of ~20 per square degree.
