Apple posted a warning to its employees on Friday telling them not to leak.

The memo has been leaked to Bloomberg.

In it, Apple says it caught 29 leakers last year and 12 of those were arrested.

Apple warned its employees against leaking to the media on Friday, Bloomberg reported.

In a leaked memo posted to Apple's internal network obtained by Mark Gurman, who regularly scoops sensitive Apple news, Apple said it had caught 29 leakers last year, and 12 of them were arrested.

"The impact of a leak goes beyond the people who work on a particular project — it’s felt throughout the company. Leaked information about a new product can negatively impact sales of the current model; give rival companies more time to begin on a competitive response; and lead to fewer sales of that new product when it arrives," said the memo published by Bloomberg.

Apple's memo said that the company had caught the engineer who had leaked details about an upcoming version of iOS earlier this year to Axios, despite the fact that there were "hundreds" of Apple employees at the meeting and "thousands more" knew details about what was discussed there.

Apple's leaking problem has been pronounced recently. In the past year, someone gave links to pre-release software to 9to5Mac, an Apple blog, which revealed the iPhone X as well as other products that had not been released. Bloomberg also regularly publishes details of upcoming Apple products.

Apple added leaks from supplier factories to its listed "risk factors" in a SEC filing in the past year.

Email the author at kleswing@businessinsider.com