Is it possible to close a PO distribution line?

We have a case where the PO distribution lines need to be changed for an amount only purchase order, which has already had payments made for the PO line.

We have split distributions (not first in first out) as we often have charges to multiple distribution lines that should be split for each voucher.

When updating the PO distribution line to add a new line, the next voucher is taking both the old no longer required line (that has been fully used in the previous vouchers) and the new line (that we want to be used).

Is there a way to close the existing distribution line so that any subsequent vouchers only have the new PO distribution line coding? Or is there another way this can be achieved.