Japan's cryptocurrency exchange DMM Bitcoin said on Friday that 4,502.9 bitcoin worth about 48.2 billion yen ($308 million) had been leaked.

It gave no details of how what it called a leak occurred but said it was investigating.

The company said it had taken measures for the leak and restricted some services.

DMM Bitcoin also said it would procure an equivalent amount of its customers' bitcoin deposits that was leaked. ($1 = 156.6400 yen)

(Reporting by Kaori Kaneko; Editing by Hugh Lawson)