The most common and most likely answer to this crossword clue is the 3 plus 9 letter word LIE DETECTORS
I've seen this crossword clue in The Daily Telegraph
L
I
E
D
E
T
E
C
T
O
R
S
Buddy explains!
The straight part
We know that "They reveal specialists in invention" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case they reveal specialists in invention = lie detectors.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.