"Until now, it was thought males injected themselves with sperm by accident during mating. But that is definitely not the case here: the sperm was clearly injected by another giant squid."

There is another possibility that cannot be totally excluded, Miske added, which is that the infusion of sperm happened during group sex.

However, that is unlikely given that chance encounters between giant squid, rare, multi-tentacled creatures which live at depths of between 300 and 1 000 metres below sea level, are few and far between.