The foreign investigation is in Vogue (6)
I believe the answer is:
latest
'in vogue' is the definition.
(I've seen this before)
'the foreign investigation' is the wordplay.
'the foreign' becomes 'la'.
'investigation' becomes 'test'.
'la'+'test'='LATEST'
'is' is the link.
(Other definitions for latest that I've seen before include "hot bit of news" , "coming after all the others" , "Most recent or most unpunctual" , "Of most recent date" , "Current" .)