Speaking to Jimmy Fallon on The Tonight Show, Allen, who voices Buzz Lightyear in the movie franchise, hinted Reeves has a part similar to his own.

"Keanu Reeves has got a great part. Even he said, gentle wonderful guy that he is, 'this sounds too much like Buzz Lightyear' and his character does have an edge to that."

Allen said the fourth instalment was "deep and moving".

But he did not reveal any more details about Reeves' character, other than to say it is smaller than Buzz Lightyear.

Last week the first trailer for Toy Story 4 was released which revealed a new character Forky, a spork which has been turned into a toy as a craft project.

Forky is voiced by comedian Tony Hale, who has appeared in hit comedies Arrested Development and Veep.

The teaser trailer revealed Forky is in denial about being a toy

The film is directed by Josh Cooley and sees the toys end up on a road trip alongside old and new friends.

Allen said the film's last scene was very emotional.

"Hanks said it best - of course, he always says stuff best - but the last scene of that movie, I couldn't even get through it. and I thought there were pages after it.

"I read it and I had to turn around from looking at it in the studio, it was so emotional."

He compared it with the classic final scene of Gone With the Wind.

"It's a 'Scarlett, I don't give a damn moment'," he said.

Toy Story 4 is scheduled to be released in the UK on 21 June 2019.