  Results of optical and NIR spectral and photometric observations of a sample
of candidate double-barred galaxies are presented. Velocity fields and velocity
dispersion maps of stars and ionized gas, continuum and emission-line images
were constructed from integral-field spectroscopy observations carried out at
the 6m telescope (BTA) of SAO RAS, with the MPFS spectrograph and the scanning
Fabry-Perot Interferometer. NGC2681 was also observed with the long-slit
spectrograph of the BTA. Optical and NIR images were obtained at the BTA and at
the 2.1m telescope (OAN, M\'exico). High-resolution images were retrieved from
the HST data archive. Morphological and kinematic features of all 13 sample
objects are described in detail. Attention is focused on the interpretation of
observed non-circular motions of gas and stars in circumnuclear (one
kiloparsec- scale) regions. We have shown first of all that these motions are
caused by the gravitational potential of a large-scale bar. NGC3368 and NGC3786
have nuclear bars only, their isophotal twist at larger radii being connected
with the bright spiral arms. Three cases of inner polar disks in our sample
(NGC2681, NGC3368 and NGC5850) are considered. We found ionized-gas
counter-rotation in the central kiloparsec of the lenticular galaxy NGC3945.
Seven galaxies (NGC470, NGC2273, NGC2681, NGC3945, NGC5566, NGC5905, and
NGC6951) have inner mini-disks nested in large-scale bars. Minispiral
structures occur often in these nuclear disks. It is interesting that the
majority of the observed, morphological and kinematical, features in the sample
galaxies can be explained without the secondary bar hypothesis. Thus we suggest
that a dynamically independent secondary bar is a rarer phenomenon than follows
from isophotal analysis of the images only.
