Insider claimed corruption was legalised (14)

I believe the answer is:

decriminalised

I'm a little stuck... Click here to teach me more about this clue!

'was legalised' is the definition.
I can't tell whether this defines the answer.

'insider claimed corruption' is the wordplay.
'corruption' is an anagram indicator.
'insider'+'claimed'='insiderclaimed'
'insiderclaimed' is an anagram of 'DECRIMINALISED'.

Can you help me to learn more?

(Other definitions for decriminalised that I've seen before include "made legal" , "No longer treated as an offence" , "no longer illegal" .)

I've seen this clue in the Sydney Morning Herald.

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