Michelle Williams has become "needier" since portraying Marilyn Monroe.

The 31-year-old actress - who portrays the legendary star in upcoming Simon Curtis-directed movie 'My Week with Marilyn' - admitted playing a character who was constantly being "abandoned" made her require people around her "an embarrassing amount".

She said: "She was someone who so needed people and was always being abandoned. I found that, playing Marilyn, I became a lot needier than I actually am as a person. I needed quite a lot from people. An embarrassing amount."

Despite the character traits she developed while playing the role, Michelle insists she feels a "responsibility" to Marilyn to do the part Justice, as she now feels like "an old friend".

She explained: "I feel a responsibility to Marilyn and a responsibility to everybody's ideas about her. She had that ability, you know, you had this desire to take care of her somehow.

"Sometimes you don't switch off from her. Especially with Marilyn, you don't want to. In some ways I feel like she's an old friend, and it some ways it feels like a crime to abandon her."