Thanks Franck! What a mystery!
On this occasion QEII visited the White City Stadium in London on 13 July 1956. Afterwards some of the nation's leading athletes were presented to HM.
The man in the photo posted by Franck was Dr Roger Bannister, the first to run the 4 minute mile.
This brooch is intriguing me. I wondered if HM was wearing 2 separate pieces, with the top one possibly being the large Nizam rose. But!! At other times I am sure that this is one piece of jewellery.
Some enlargements from other photos. I hope that they will jog someone's memory. Bryce, do you have any ideas?