We have a 1" copper pipe running between the floor joists
It has been tapped with one of those taps that drill a hole in the copper
when attached.
Later, the tap was shut off and not used anymore.
Recently the tap has started leaking.

This was done by the previous owners and we don't even know why the line was
tapped.

The problem is that the location of the tap is nearly imposssible to access
because it's right above a door frame.
Therefore the pipe cannot be cut or welded to replace the tapped segment.
Also the pipe cannot be easily removed because it's about 24' long and safe
access to one end is also impossible without destroying a wall.

What are my options to fix the leak ?