The flow of current to a variable speed motor is controlled by the converter. The current is non-sinusoidal due to the non-linearity of the converter and the generation of harmonic currents. Generally forming of sneak circuit in power system including semiconductor devices such as diode and thyristor especially with higher harmonics is possible. Please note to form of tuned sneak circuit probability making with C1,C2 and L in following figure. You can check harmonic content of that leakage current (2A) with an oscilloscope and influence of external capacitor bank with temporary remove it. 