Nestle is to open its first factory in Japan in more than 25 years because of demand for exotic flavours of Kit Kat.

While traditionally the wafer snack has been made using milk chocolate, dozens of different flavours are proving popular in Asia.

Flavours like wasabi and green tea have helped Kit Kat sales in Japan grow by 50% since 2010, Nestle said.

The factory will focus on the more expensive versions of the snack which have been a hit with tourists.

Spending by visitors on confectionery has more than tripled in the past four years, according to government figures, to about $1.2bn (£922m).

"Over the past few years, Nestle was able to demonstrate good growth in Japan despite a challenging environment", a Nestle spokesman said.

"This good performance can be explained with our strategic focus on innovation and premium, for example with Kit Kat."