The fascinating story of those who won’t stop searching for Nessie. Plus: Claudia Winkleman sits in for Graham Norton. Here’s what to watch this evening

9pm, BBC Two
In 1961, the Loch Ness Investigation Bureau started monitoring the loch 24/7. By the 70s, a Japanese pop promoter, Yoshio Kou, led the International Loch Ness Monster Search Party. And 2023 saw the biggest Nessie hunt in more than 50 years. The beast has kept tourists coming for decades, and this documentary tracks the people who have been most obsessed with finding it. Hollie Richardson