According to this account, the Shah remained deeply worried about Mosaddeq's influence, even while incarcerated. Roosevelt reports the Shah is prepared to execute Mosaddeq (after a guilty verdict that is a foregone conclusion) if his followers and the Tudeh take any threatening action.
Kermit Roosevelt Jr.
National Security Archive: <a rel="nofollow" class="external free" href="https://nsarchive2.gwu.edu/NSAEBB/NSAEBB435/">https://nsarchive2.gwu.edu/NSAEBB/NSAEBB435/</a>