Whitney Houston's Sister-In-Law Backs Off Foul Play Suspicion

Pat Houston was at LaGuardia Airport yesterday morning when our photog asked her if she believed foul play was involved, and she said no.

You'll recall ... Pat told Oprah she did not know how Whitney ended up in the tub, suggesting her death was something other than an accident. It's unclear if Pat knew if Whitney's body was found face down in the tub and if that's why she had doubts at the time.