The most common and most likely answer to this crossword clue is the 7 letter word USURPER
I've seen this crossword clue in The Daily Telegraph
U
S
U
R
P
E
R
More clues leading to the result USURPER
- Quietly stops one taking excessive interest in trespasser
- One wrongly claiming loan shark hides money
- He generates huge interest seizing power — Richard III?
- Mum’s curry — poetry on occasion, one assumes!
- One taking interest stealing power?
- Unscrupulous financial operator seizing power, one who takes over
- Criminal seizing power in America and Peru possibly? Right
- He dispossesses loan shark without a penny
- Soft-hearted moneylender who enters office uninvited
- He enters office uninvited
Buddy explains!

The straight part
We know that "Criminal seizing power" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case criminal seizing power = usurper.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 USURPER mean?
USURPER noun- One who usurps.