Recovered soldiers made an allegation (9)
I believe the answer is:
reclaimed
'recovered' is the definition.
('reclaim' can be a synonym of 'recover')
'soldiers made an allegation' is the wordplay.
'soldiers' becomes 're' (Royal Engineers).
'made an allegation' becomes 'claimed' (I can't justify this - if you can you should believe this answer much more).
're'+'claimed'='RECLAIMED'
Can you help me to learn more?
(Other definitions for reclaimed that I've seen before include "Recovered, like fenland" , "Retrieved" , "Salvaged" .)