cannot drop a tablespace which never exists in pg_tablespace

[Bharani SV-forum]

 
cannot drop a tablespace which never exists in pg_tablespace

I remember i had create previously an tablespace named " mq_data" , but cannot 
find in pg_tablespace listing.
if i try to create the same tablespace name, it is giving error as " already in 
use as a tablespace"how to force drop the pointer entry and the tablespace from 
postgres