YOU SAID:
We have reason to believe they may be planning to sell the sword there.
INTO JAPANESE
そこで剣を売ろうとしているのかもしれません。
BACK INTO ENGLISH
They may be selling swords there.
INTO JAPANESE
彼らはそこで剣を売っているかもしれません。
BACK INTO ENGLISH
They may be selling swords there.
That didn't even make that much sense in English.