1- It was a forced gift from a child king who was not aware of the value of that diamond.
2- It is said that it was a well played game at the last moment as exchange of pagris (caps) in between and cheater British Officers forced the little king to give the diamond.
3- It is related to India indeed but Maharaja Dileep Singh shifted to France and there loads of women looted him of his wealth very well.
4- The family members are still there in France and Patiyala.