Helen Mirren was given a diamond-encrusted safety pin by Russell Brand after shooting their new film together.
The actress, who was being interviewed on breakfast television show Daybreak gushed that the comedian is the "goodest boy you could possibly meet".
Known for her roles in The Queen, Calendar Girls and most recently Red, the star plays Russell's nanny in the movie Arthur, a remake of the 1981 comedy.
Mirren said that Brand had given her the sparkling present at the end of the film "as a prize".
This week, unusual diamond trinkets sold at a Sotheby's auction of the jewels Edward VIII had given to his partner Wallis Simpson.
Among the 20 interesting items that belonged to the royal couple in the event's catalogue was an articulated onyx and diamond bejewelled panther bracelet that sold for £4.5 million, making it the most expensive bracelet ever to have gone under the hammer.