Capcom has shipped four million units of PSP title Monster Hunter Freedom 3 over its first month on sale, and purely within Japan.

The publisher claims this makes the game the PSP's fastest selling title ever, though has yet to reveal what proportion of shipped titles extrapolated to sales.

Capcom nonetheless claimed that Freedom 3 takes Monster Hunter series total sales to 17 million. It also projects that the game is on course to be Japan's best-selling title for the 2010 financial year.

Monster Hunter Freedom 3 was released in Japan on December 1, and will arrive in Western territories later this year.