Lindsay Lohan has been banned by doctors at her rehab centre from attending the premiere of her latest film.The actress - who checked herself into the Wonderland Center in Los Angeles'Laurel Canyon last Wednesday - was hoping to attend the launch of crime drama 'Chapter 27' at the Sundance Film festival in Park City, Utah this week. However, she was banned from attending by her doctors, who feared it might harm her progress. A source said: "The doctors have told her she has got to stay put as leaving the centre would interfere with her treatment."The medics were apparently worried the 20-year-old might give into temptation and start drinking again. The source added: "Park City is such a party town during the Sundance Festival that it was feared attending the premiere might prove too much of a temptation."However, Lindsay has been allowed to leave the centre during the day to film her new movie, 'I Know Who Killed Me'. Her publicist Leslie Zelnick said: "She will continue working but will spend her nights at the recovery facility."