BBB,
The JAR reference you requested in your initial posting is JAR-FCL 1, Section 1, Subart A, item 1.060. JARs section 1 can be found
here
As you will see, this limitation applies to commercial air transportat operations only. It is, however, correct that a few JAA member states have stricter rules, and that pilots, on ramp checks in at least one country, have been 'asked' to leave the crew and pax home.
C'est une malade!
cheers,
redbar1