The most common and most likely answer to this crossword clue is the 10 letter word MISLEADING
I've seen this crossword clue in The Daily Telegraph
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More clues leading to the result MISLEADING
Buddy explains!

The straight part
We know that "Deceptive" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case deceptive = misleading.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does MISLEADING mean?
MISLEADING verb- To lead astray, in a false direction.
- To deceive by telling lies or otherwise giving a false impression.
- To deceptively trick into something wrong.
- To accidentally or intentionally confuse.
- A deception that misleads.
- Deceptive or tending to mislead or create a false impression.