Rapper 50 Cent has tried to reassure fans that he is OK after he posted pictures of himself on his website looking shockingly thin.

50 Cent (left picture shows his major weight loss)

The usually muscle-bound star lost almost four stone in just nine weeks to play an American football player suffering from cancer in his new movie.

50 Cent went from 214lbs to 160lbs after spending three hours a day on a treadmill and surviving only on a liquid diet.

The US rapper/actor - real name Curtis Jackson - wrote: "I lost 54lbs for it. I was starving."

Some people expressed shock at the pictures.

A post by Patricia Archibald on the star's website said: "You look haunted! What is behind those lost eyes?"

Another shocking picture from his website

Others refused to believe that the pictures were actually of him.

Medina said: "This aint no damn 50 cent.. this is bull crap!", while fleXeR said: "Fake! look at his ears son."

50 Cent's method acting echoes that of British star Christian Bale who lost 63lbs for his role in the dark mystery film The Machinist.

Bale went from 185lbs to 122lbs to look like he 'had not slept for a year' and did it by cutting out most foods and lots of exercising.

50 Cent is currently on tour and is now putting the weight back on. In recent weeks, he has been pictured in concert looking healthier.

He reassured fans: "I've been eating. I'll be back in shape in no time."

He also had his tattoos removed for the movie Things Fall Apart, which he wrote himself.

The film is due out next year.