London, Dec. 16 : Bollywood star Aamir Khan roamed around the streets of Kolkata in disguise as part of an innovative way to promote his forthcoming film ''3 Idiots''.

In a unique marketing strategy Khan has gone incognito before the film''s release.

Aamir Khan walked down the streets of Kolkata and met locals. He also went knocking on the doors of Saurav Ganguly posing as a fan. But the guards stationed there failed to recognize him and disallowed his meeting with the former Indian cricket captain.

Later in the evening, he again paid visit to Ganguly''s residence in his normal looks and met him. Aamir''s wife Kiran Rao also accompanied him.

He spent the entire evening and better part of the night at Ganguly''s house. Khan also presented a ring to former ace batsman on the occasion.

The star cast of the film, during a media conference held in Mumbai on Friday, disclosed that Khan would be on an adventure trip throughout the country for two weeks.

Earlier he went to Varanasi, which is her mother''s ancestral hometown.

Khan has described this ploy as an ''Alternative Reality Game'' (ARG) of Three Idiots, and whoever successfully identifies Khan in his disguise would be get free tickets for the movie and as a bonus Khan would spend New Year''s night with the lucky winner and his family.

''3 Idiots'' is the celluloid adaptation of author Chetan Bhagat''s best selling novel ''Five Point Someone''.

Directed by Rajkumar Hirani, the film essays the story of three friends whose dismal grade point averages at the Indian Institute of Technology influence their friendship, love life and career choices.

Sharman Joshi, Aamir Khan and R. Madhavan who are starring together in this film, were also co-stars in the critically acclaimed ''Rang De Basanti''.

The film, set for release on December 25, has brought Khan and producer-director Vidhu Vinod Chopra together for the first time.

The film also stars actor Kareena Kapoor in the female lead. (ANI)