(Adds comment from Apple Japan; Tokyo tax authorities decline to comment)

TOKYO, Dec 27 (Reuters) - Apple Inc's Japan unit is being charged 13 billion yen ($98 million) in additional taxes for bulk sales of iPhones and other Apple devices to foreign tourists that were incorrectly exempted from the consumption tax, the Nikkei newspaper said.

Citing unidentified sources, the Nikkei reported on Tuesday that bulk purchases of iPhones by foreign shoppers were discovered at some Apple stores with at least one transaction involving an individual buying hundreds of handsets at once.

Japan allows tourists staying less than six months to buy items without paying the 10% consumption tax, but the exemption does not apply to purchases for the purpose of resale.

Apple Japan is believed to have filed an amended tax return, according to Nikkei.

In response to a Reuters' request for comment, the company only said in an emailed message that tax-exempt purchases were currently unavailable at its stores. The Tokyo Regional Taxation Bureau declined to comment.

The iPhone maker's Chief Executive Officer Tim Cook visited Japan earlier this month and announced that the company had invested more than $100 billion in its Japanese supply network over the last five years. ($1 = 132.9000 yen) (Reporting by Akanksha Khushi in Bengaluru, Kiyoshi Takenaka in Tokyo; Editing by Chizu Nomiyama and Kenneth Maxwell)