All 4 Uses

inquiry
in
Harry Potter (#2) and the Chamber of Secrets
(Edited)

-ABSOLUTELY DISGUSTED — YOUR FATHER'S FACING AN INQUIRY AT WORK, IT'S ENTIRELY YOUR FAULT AND IF YOU PUT ANOTHER TOE OUT OF LINE WE'LL BRING YOU STRAIGHT BACK HOME.
p. 88.7

inquiry = questioning or investigating
Mr. Weasley was facing an inquiry at work.
p. 89.1 *
"You can't let Harry deal with that thing on his own."
"Let's ask for an inquiry..."
p. 170.3

inquiry = investigation
It had been clipped out of the Daily Prophet, and it said: INQUIRY AT THE MINISTRY OF MAGIC Arthur Weasley, Head of the Misuse of Muggle Artifacts Office, was today fined fifty Galleons for bewitching a Muggle car.
p. 221.8

Definitions:

(1) (inquiry)
a question or investigation -- especially one meant to gather information or find out the truth
(2) (meaning too rare to warrant focus)