The White House learned this summer that the National Security Agency had tapped the phones of world leaders and ordered a halt to some of the eavesdropping, The Wall Street Journal reported Sunday.

Quoting unidentified U.S. officials, the newspaper’s website said the wiretapping of about 35 foreign leaders was disclosed to the White House as part of a review of surveillance programs ordered by President Barack Obama after NSA contractor Edward Snowden leaked classified details of the NSA’s phone monitoring systems.

The White House ordered a halt to the monitoring of German Chancellor Angela Merkel and unspecified other leaders, the newspaper reported. The Journal report did not specify who gave the shutdown order or the date it was issued.