While not mentioning any numbers, IO's Niels Jorgensen "can confirm" they've reduced the studio's headcount. It's a "natural part" of game development.
“I can confirm that we have made some internal changes at IO Interactive which has regrettably resulted in the loss of some jobs," said general manager Jørgensen.
“This is a natural part of any studio's existence when you ramp-up and ramp-down on projects to ensure you have the right level of resource and expertise within the studio. We genuinely wish those who have been affected by this, the best of luck for the future.”
Square Enix bought IO Interactive in 2004 for £23 million. Their latest release has been Kane & Lynch 2: Dog Days which climbed to the top of the charts. Recently the voice actor for Number 47 revealed ais in the works.