The most common and most likely answer to this crossword clue is the 8 letter word RANSOMED
I've seen this crossword clue in The Guardian
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Buddy explains!

The straight part
We know that "demanded money for freedom" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case demanded money for freedom = ransomed.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 RANSOMED mean?
RANSOMED verb- (14th century) To deliver, especially in context of sin or relevant penalties.
- To pay a price to set someone free from captivity or punishment.
- To exact a ransom for, or a payment on.