Aviation (Preclearance) Act 2009
In-transit preclearance: where traveller is refused permission to enter.
11.— (1) Where, on in-transit preclearance, a traveller is refused permission to enter, the air carrier or the aircraft commander concerned shall be responsible for any costs (including, where necessary, the traveller’s accommodation and maintenance costs) arising from the removal of the traveller and his or her goods—
(a) to the state or other territory in which the traveller boarded the aircraft, or
(b) where the traveller is not a citizen of that state or a resident of that state or territory, to the state or territory of which the traveller is a citizen (in the case of a state) or a resident (in the case of a state or a territory).
(2) Nothing in subsection (1) shall prevent the air carrier or the aircraft commander from recouping from the traveller in any court of competent jurisdiction the costs expended pursuant to that subsection.