A power MOSFET has a circuit structure between source and drain equivalent to a diode.
When reverse voltage is applied between the drain and source of the power MOSFET, current flows in this body diode as shown in the following Fig.
MOSFETs (Silicon type) which specify reverse drain current IDR (DC) and reverse drain current (pulsed) IDRP, must not send current over the IDR and IDRP of the absolute maximum rating.
It is necessary to take the rising temperature into consideration by the flowing current through the body diode.
The rising temperature does not exceed the channel temperature Tch of the absolute maximum rating.
Please consider temperature derating, and confirm that there is no problem with actual equipment.
For MOSFETs (Silicon type) which does not specify reverse drain current IDR (DC) and reverse drain current (pulsed) IDRP, contact your local Toshiba sales representative.