Gate-induced drain leakage current in accumulated metal-oxide-semiconductor field-effect transistors is pumped out completely by the body, while the source current should be zero due to the barrier of the p/n junction between the source and the accumulated channel. In this work, we report the observation of the current peaks in the source current versus gate voltage characteristics of p-channel transistors when the devices are biased at the accumulation regime. The source current vanishes when the temperature exceeds 11 K. The source current can be enhanced dramatically as the transistors are exposed to a high magnetic field perpendicular to the channel. We believe the Fermi-edge singularity may be responsible for the resonant source current peaks. © 2003 American Institute of Physics.