The film will go out on the BBC Two channel as part of the Natural World strand this week. The BBC acquired it from NHK Enterprises, the commercial arm of the Japanese broadcaster.
The 1x52mins doc is a coproduction between NHK and Discovery with support from European broadcasters Arte and ZDF.
It follows the efforts of a team of international scientists to dive deep into the ocean to capture the giant squid on camera after a decade-long research project.
NHK has also licensed the doc to Spanish pubcaster TVE and its Swedish counterpart SVT. Both will air it this November.
It has already aired on NHK and Discovery in the US. Discovery also took pay TV rights for its international channels.