Even in case of forgery one paper appears twice (5-5)
I believe the answer is:
fifty-fifty
'even' is the definition.
(I know that even can be written as fifty-fifty)
'in case of forgery one paper appears twice' is the wordplay.
'in' indicates putting letters inside.
'case of' means to remove the middle letters (outsides of).
'one paper' becomes 'i' (UK newspaper).
'appears' becomes 'ft' (I can't justify this - if you can you should give a lot more credence to this answer).
'twice' shows that letters should be duplicated.
'forgery' with its middle taken out is 'fy'.
'i'+'ft'='ift'
'fy' placed around 'ift' is 'fifty'.
'fifty' doubled is 'FIFTY-FIFTY'.
(Other definitions for fifty-fifty that I've seen before include "Evens" , "Evenly divided" , "Equally" , "Fairly" .)