Recent footage from the North's state television network showed Jon Il-chun standing closer to Kim than Kim's heir apparent son, Kim Jong-un, on an inspection tour of a supermarket in Pyongyang.
Kim Jong-un is being groomed to succeed his father Kim Jong-il as the country's next leader in what would be the country's second hereditary power transfer.
Jon and Kim Jong-un were also seen standing side by side on an escalator at the Kwangbok Area Supermarket, according to recent photos released by the North's official Korean Central News Agency.
Jon, who has rarely been exposed to media, was last seen on Kim's trip to a factory in July.
He heads Office 39, which has often been referred to as Kim's "personal safe" for its role in raising and managing secret funds for the North Korean leader.
The office is also believed to be involved in counterfeiting US$100 bills and drug trafficking.
Last year, the United States blacklisted Office 39 as one of several North Korean entities to come under new sanctions for its involvement in illegal activities such as currency counterfeiting.