Possible Clues:

• Be suspicious (3 words)
• Be suspicious, so to speak
• Have suspicions, lets alarm off
• Suspect that something is wrong
• Suspect trickery as real malt's blended
• Have a sneaking suspicion
• Suspect chicanery
• You'd expect a whiff of this when Bogie's out with the pack - is that suspicious?
• Suspect everybody returned during term as planned
• Ms Fitzgerald's aboard second faulty tram -- be wary!