Freddie Prinze Jr. lifts lid on Sarah Michelle Gellar's secret cameo

Freddie Prinze Jr. is "glad" he was able to keep quiet about Sarah Michelle Gellar's secret cameo appearance in I Know What You Did Last Summer.

The actor returned for the new sequel almost 30 years after he starred in the original 1997 slasher opposite his wife Sarah and film fans initially thought the Buffy The Vampire Slayer star would be unable to join him onscreen because her character met an untimely end in the first film. However, it has since been revealed Sarah's beauty queen alter-ego Helen returned for a dream sequence and Freddie was thrilled to have been able to keep it secret until the movie hit cinemas.

Freddie told PEOPLE he "knew from jump" that Sarah would be in the new film, adding: "We were all really excited for audiences to get to see that and get a little bit of extra love that they weren't expecting.

"It's nice to know a secret, and to know how well-received it's going to be, months and months before it ever goes out there.

"To hear the reaction that people have had, because I know some other people that have seen it, they're all like: 'Oh, my God, you didn't tell me! That was the best.'

"I'm like, 'Yeah, it was the best one. Everybody always loves her.' To give people another taste of that, I just think was awesome. I'm glad everyone made it happen."

The new film's director Jennifer Kaytin Robinson admitted she always wanted her pal Sarah to make a surprise appearance, and they even had the costume department recreate the beauty queen tiara the actress wore in the first film.

Robinson told the publication: "As a super fan of this franchise, I was never not going to put [Sarah's character] Helen Shivers in the movie. And I didn't lie - she is dead ...

"I'm so excited about the results. I feel like it’s just so fun. We recreated the Croaker Queen crown. That is an exact replica of the crown from the original movie. I really went for it in trying to create this David Lynch-y Helen Shivers dream sequence."