The most common and most likely answer to this crossword clue is the 3 plus 6 letter word TEA LEAVES
I've seen this crossword clue in Financial Times
T
E
A
L
E
A
V
E
S
More clues leading to the result TEA LEAVES
- They steal bird by roof's edge
- Light-fingered types with permission to interrupt meals
- Burglars duck atop roof-edge
- Thieves duck where icicles hang down
- Thieves disappear in a set dispersing
- Duck next to edge of roof, the result of having a drink?
- Everton, say, almost goes – or remains in the cup?
- Robbers used to predict the future
- Cockney criminals going to pot?
- Cockney thieves may end up in hot water
Buddy explains!

The straight part
We know that "Thieves" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case thieves = tea leaves.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 TEA LEAVES mean?
TEA LEAVES noun- (usually used in the plural) A dried fragment of a leaf of the tea plant used in making the drink tea.
- A thief.