If the woman can be separately interviewed away from her ethnic community, where she can easily communicate without being in the presence of her siblings, or spouse, or anyone, that could be one way to determine whether it is a forced marriage or not.
Also, in the U.K. they have introduced a practice that a woman can carry a spoon in her underwear and when she passes through the radar scanner, it starts buzzing. That would tell the immigration officers that the woman was taken from her country for forced marriage purposes.
There are different—