The most common and most likely answer to this crossword clue is the 8 letter word FOGBOUND
I've seen this crossword clue in Independent
F
O
G
B
O
U
N
D
More clues leading to the result FOGBOUND
Buddy explains!

The straight part
We know that "detained by undesirable elements" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case detained by undesirable elements = fogbound.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 FOGBOUND mean?
FOGBOUND adjective- Enveloped in fog to such an extent that movement is dangerous or impossible