Washington CNN  — 

Germany’s Federal Prosecutor’s Office has dropped a probe into allegations that the National Security Agency had bugged the phone of German Chancellor Angela Merkel.

The prosecutor’s office in Karlsruhe said in a statement Friday that its investigation into accusations by former NSA contractor Edward Snowden had uncovered insufficient evidence to launch a successful prosecution.

Snowden had leaked documents that alleged the NSA monitored global data and had an especially large operation in Germany. German authorities launched a wide-ranging probe last June.

The allegations had led to strained relations between Germany and the United States, and led to criticism, both from within the United States and outside, that the U.S. was overreaching in its efforts to thwart terrorist attacks.

At a press conference with Merkel in February, President Barack Obama acknowledged that Snowden’s charges had harmed the relationship, but asked for the nation to place the news within the broader Germany-U.S. alliance.

“Occasionally I would like the German people to give us the benefit of the doubt, given our history, as opposed to assuming the worst – assuming that we have been consistently your strong partners and that we share a common set of values,” Obama said.