Cryptic crossword clue
Ringleader I put inside after being sent back for new case 7

The most common and most likely answer to this crossword clue is the 7 letter word RETRIAL

I've seen this crossword clue in The Sunday Telegraph
R
E
T
R
I
A
L


Buddy explains!

The straight part
We know that "new case" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case new case = retrial.
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 RETRIAL mean?

RETRIAL noun
  1. A second trial, by the original court, if the original trial was found to be improper or unfair

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