Thanks guys - sorry for the confusion
They didn't look like any crepuscular rays I'd seen before since they were *only* pointing along the ecliptic, and nowhere else in the sky, but given the exposure settings I agree it was unlikely to be zodiacal light.
They were also more of an "absence of pink light" rather than the presence of sunset light that I normally see - must be a weird object/stray cloud somewhere in the distance.
Anyway, I'm happy to agree that it was just a crepuscular ray - thanks for the correction.
For the record, Luis, I have recorded "real" zodiacal light from dark skies + no light pollution + dawn in Summer