SAO PAULO, Jan 12 (Reuters) - Brazil's Minas Gerais state-controlled energy company Cemig removed five executives that are under investigation by state prosecutors, the company said on Tuesday.

Cemig said the investigation was sealed and did not say why the executives were being investigated. It added in a statement that they were removed as a preventative measure.

The company confirmed supply and logistics superintendent Paulo Vanelli had been removed. Neither Vanelli nor the other executives could immediately be reached for comment.

A total of 15 employees had lost their positions, three people familiar with the matter said, asking not to be identified as the information was not public.

Executives from legal and communication departments were also removed from their posts, a third person said. (Reporting by Luciano Costa Writing by Sabrina Valle; Editing by David Gregorio)