Gas thread (safefill)

Hi everyone, I have a 10kg safefill lpg bottle Iv recently noticed there's a very small leak coming from the neck of the bottle, it seems to be the thread where the regulator connects into the bottle. (Maybe its been cross thread at some point im not sure ).

Does anyone know of a remedy, or know of anywhere i could get the bottle thread repaired or replaced ?

Many thanks for any advice.

Jed