What is the ruling of the Sharia regarding confronting a partner who used money designated for gold and currency exchange trading to purchase a car, which is suspected to be for personal use?

The questioner incurs no sin by reviewing with the one to whom she gave her money for mudarabah (definition), and inquiring about what he is doing with her money. If it becomes clear that he took the money for himself and did not engage in mudarabah with it, then the money is guaranteed by him and he must return it to the questioner. However, if he did indeed engage in mudarabah with the money and adhered to his agreement with the questioner, then he is entitled to his stipulated share of the profit, and he is entitled to the one-year period for which he set the mudarabah, because a time-bound mudarabah is valid if there is mutual consent.