Robbert Broekstra was a Dutchman, he died as Pedro said some years ago and he lived in the city of Gouda if i'm right. In the Netherlands they called them a "media naturist" because as ever there was something about nudism or naturism on television he appeared in it. He was photographer and initiator of the "Vrienden van Randstad Natuur" nudist and photography club. A lot of his pics, reports were published in the formerly well known German nudist magazine Sonnenfans and the British magazine Health and Efficiency (H&E). Not everyone in the serious Dutch naturist scene liked him as you can understand.
He and his nudist group were also involved in 2 nudist movies made by Dave Ball: "Summer in Holland" and "Winter in Holland", both made in the end of the 80's and the beginning of the 90's. See also this thread:
https://forum.oneclickchicks.com/showthread.php?t=68781
I will look in my collection if i find some pics related to Robbert Broekstra. By the way he died after some problems with his heart.
