This news is deeply troubling.

a deeply troubling development.

very serious and deeply troubling.

I am deeply concerned by these inconsistencies. ... I intend for the committee to get to the bottom of this.

I think that Mr. Haddam's remarks raise some deeply troubling issues as to what exactly was going on during the period in time in question.

to be extremely troubling. They seem to reflect the work of a deeply committed ideologue.