One flash of her neck and Johnny Depp was done for

French singer Vanessa Paradis stole Johnny Depp's heart in an instant with a flash of her swanlike neck, the Hollywood star told Reuters in an interview.

Speaking before next week's premiere in Paris of his new movie The Tourist, where his character falls for a femme fatale played by Angelina Jolie, Depp said personal experience means he too believes in love at first sight.

"I certainly believe in an instant and profound connection with someone, which is what happened to me," Depp said, wearing his trademark fedora hat."  

"I had an instant connection with Vanessa's back and neck ... I was fascinated with this neck and she turned, looked straight at me and wandered across the room and I thought: 'you're done, you're up shit creek."

Depp and Paradis, also a model and actress, have become one of Hollywood's favourite couples since they met in 1998. They have two children together and split their time between Paris, the south of France, New York and the Hollywood Hills.

In The Tourist, Depp plays a bumbling maths teacher swept off his feet by Jolie's glamorous Grace Kelly-esque character, who then drives him to madness by exposing him to crazy situations as he tries to prove his love.

In one scene, Depp finds himself bounding across the rooftops of Venice wearing a pair of pale blue pyjamas — unlikely garb for the 47-year-old heartthrob who admits he's not a fan of nightwear in real life.

"I have never been a pyjamas guy," Depp  chuckled.  

"I rarely wear them, but when you do there's something that kind of takes you back to some weird psychological place, safety and comfort and being a kid maybe."

The hapless Maths teacher role marks a break from Depp's trademark of strong and slightly peculiar characters.

The Pirates of the Caribbean star worked with the eccentric Tim Burton in the upcoming film Dark Shadows and for the future he has an eye on trying Shakespeare's Hamlet, something he said legendary actor Marlon Brando said he should do before he got too old.

But Depp would give it his own twist, he said, putting on a hint of an Irish accent.   

"It would be fun and interesting to do Hamlet on a small scale and take a different approach. I've asked dialect experts and they say at the time of Shakespeare it would have been closer to a Dublin accent," he said.    

"It's something I wouldn't mind tackling."