The exam was staged at schools across New Zealand last week, the news portal stuff.co.nz reported on Monday.
It included a song by the acappella group Wise Guys. The five-man group has often been invited on international tours by the Goethe Institute, has played at several major church gatherings, and is generally considered mild stuff in Germany.
The Year 12 students - aged around 16 and 17 - were played the song Relativ in their exam, something which in itself appears to have been an innovation.
The lyrics are from a man's point of view, running through a list of comparisons, claiming to be relatively smart compared with Heidi Klum, but relatively stupid compared with Steven Hawking - relatively tall compared with a piece of gravel, but relatively small compared with a cliff.
He then talks about liking the object of affections, "relatively a lot", but being incapable of expressing his feelings.
He continues to talk about how the person he is singing to is, "nicer than my neighbour, and I expect that in bed with you, quite a lot would be possible."
It was this line which reduced some students to laughter - and others to tears as they failed to work out what was happening. One teacher told stuff.co.nz she thought the song was "totally inappropriate" for Year 12 students - although she also said she had had difficulty understanding the song herself.
The New Zealand exam authority's deputy chief executive Richard Thornton said the song had been chosen because "it was felt it would engage the candidates" and had been chosen with 16- and 17-year-olds in mind.
Further national language exams are due soon in Spanish and French - with teachers across New Zealand wondering what their students should expect.