The most common and most likely answer to this crossword clue is the 10 letter word TECHNOCRAT
I've seen this crossword clue in The Guardian
T
E
C
H
N
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T
More clues leading to the result TECHNOCRAT
- One from skilled elite Cochrane demolished in Times
- Contract he arranged for a practical expert
- Whitehall scientist makes contact with her
- Authority in control, he has contract for renegotiation
- Scientist developed trench coat
- Tailored trenchcoat for scientific expert
- College car not in order for a modern politician?
- Trench coat altered for powerful scientist
Buddy explains!

The straight part
We know that "Authority in control" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case authority in control = technocrat.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 TECHNOCRAT mean?
TECHNOCRAT noun- An advocate of technocracy.
- An expert in some technology, especially one in a managerial or administrative role.
- An individual who makes decisions based solely on technical information and not personal or public opinion.