War das im Abendprogramm oder nachmittags fuer Kinder?
Vielleicht "Das Geheimnis der Mine" (Mystery in the Mine)?

Hier ist ein Foto: [www.cftf.org.uk]

Mystery in the Mine
128 mins (8 episodes)

The exciting story of a boy and girl and their young scientist friend who foil the efforts of an International Gang to get a rare ore out of the country.
Produced by Merton Park Productions Ltd. Story by Peter Ling. Director James Hill. Producer Frank A. Hoare.
With: Ingrid Garden, Stewart Guidotti, Peter Copley, Elwyn Brook-Jones.

•Episode 1. Secret Agent.
•Episode 2. Danger in the Dark,
•Episode 3. Trapped Underground.
•Episode 4. Poison Gas.
•Episode 5. Sudden Peril.
•Episode 6. Hot on the Trail.
•Episode 7. Out of Control.
•Episode 8. Desperate Finish.