"Of course New Zealand people do a lot of bungy jumping and we're told it's because they've got such wonderful scenery and such great bungy [jumping].
"But it's not - what New Zealand has got is sod all ... Nothing there, there's nothing there."
Foster then said the best thing about New Zealand was Christchurch.
"And even that had an earthquake."
Foster said that for the average New Zealander, with sod all except our shaky isles, there must come a point when we think: "Well I might as well jump myself off a bridge, just to see what happens."
To which his co-presenter quipped: "It's like trial suicide, isn't it?"
Foster explained that our inclination for extreme sports was - again - because there was nothing else to do, and because it was our last resort to "get some emotion".
One day soon, he said, there would be a new sport where people used nail guns to nail their hands to trees.
"And people will say, 'Did a New Zealander think of that?' and you'll say 'Yeah, it's because they've got nothing else there'."
Foster's view greatly differs from that of his fellow countrymen, who have said New Zealand has long been one of their favourite holiday destinations, according to Tourism New Zealand.
Its research showed that 231,764 British travellers made it to New Zealand in the year to November.
Overall, visitors from the UK rated their holiday in New Zealand at 9.3 out of 10.
Toby Foster did not reply to the Herald's queries about his rant.
SHEFFIELD
* It's best known for its ailing steel industry.
* The Lonely Planet Guide lists only 12 things to do in the city - the top being an Italian restaurant.
* For a few weeks of the year it hosts the world championships for snooker - pool's doddery old relative.
* It's the bleak and depressing backdrop for The Full Monty film.
* Its residents use all five vowel sounds when only one is required.