Aamir Khan, who has been criss-crossing the country in disguise to promote his new film "3 Idiots", has been denied permission to spend a day with the Indian Army's cadets at the Officers Training Academy (OTA) in Chennai, Tamil Nadu.

"The film star had sent a request to the defence ministry to spend a day at OTA. But it has been declined and the ministry has not given any reason for it," sources said.

Aamir wanted to interact with the cadets and wanted to see their lives from close quarter.

Nearly 500 cadets from the Short Service Commission cadre pass out from the military institution every year.

It is yet not clear whether Aamir wanted to spend a day at the army institution for his future project or to promote "3 Idiots" releasing this Friday.

The movie revolves around three friends and their college days and marks Aamir's return to the big screen after a year. The actor has created a buzz because of the innovative ways he has been promoting the film.

To market the film, Aamir has been travelling across the country in different get-ups. His travels have so far taken him to Varanasi, Madhya Pradesh's Chanderi district, former cricket captain Sourav Ganguly's home in Kolkata, Jaipur and Punjab's Faridkot district.