In a suspicious manner; with suspicion.

So as to excite suspicion.

adverb. In a way suggesting suspicion.

adverb. In a way that arouses suspicion.

adverb. Causing suspicion.

adverb. To a degree that makes one suspect something.

adverb. with suspicion

"Another lawsuit is pending in Germany against the Opel division of General Motors, this one for a version of the Brahms "Lullaby" performed in what he calls a suspiciously Waitsian voice."

ambitiously  expeditiously  surreptitiously  viciously