This was a children's show I watched in the summer holidays in the 70s. An import from abroad. One of several that retained the original foreign language dialogue, no dubbing or subtitles, with a narrator explaining the plot.

The plot, as far as I recall, centred around a new boy in school. I'm pretty sure he had a younger sister. At the end he was accused of some scandal - theft, perhaps. He had to leave town. And then evidence turned up showing his innocence. The other children ran to the station, but arrived just as the train left.

Anyone remember this? What was it called?

It wasn't The Boy From 5B. That was a different show. But shown round about the same time.