A comparator input is a pin configured in analog mode. In analog mode, the pin's weak pull is disabled, and its leakage current is specified in the Port I/O DC Electrical Characteristics section of the datasheet, and not in the Comparator Electrical Characteristics section.
For example, the C8051T60x leakage current is max +/- 1 µA (Table 8.3 of the revision 1.2 datasheet).
Comparator Input Leakage