Multiferroic nanoparticles of BiFe0.95Co0.05O3 (BFCO) with different sizes were prepared by low temperature acetate precursor based modified sol-gel method. X-ray diffraction (XRD) measurement revealed rhombohedral phase of nanoparticles. Crystallite size increases from similar to 41.05 nm (700 degrees C) to similar to 48.42 nm (800 degrees C). The dielectric constant and loss tangent were studied as a function of temperature at different frequencies. The appearance of dielectric anomalies around antiferromagnetic transition temperature prove the existence of possible magnetoelectric (ME) coupling. Possible present ME coupling has been studied by performing magnetodielectric (MD) measurements at room temperature. The strong variation in dielectric constant and loss has been found under the influence of magnetic field at room temperature. The magnetoimpedance (MI) measurement was studied to separate out intrinsic and extrinsic MD effect. Spin spiral suppression at nanoscale with crystallite size less than similar to 62 nm and lattice strain, arises due to Cobalt doping, play an important role in controlling multiferroic properties.