Running a GUI program haults the calling program (linux)

[Kryptxy]

I want to run a GUI program (transmission-gtk) from python. This is what I do:

import subprocess
subprocess.Popen(['transmission-gtk', link], stdout=subprocess.PIPE, stderr=subprocess.PIPE)

Where `link` is some magnetic link.

This command opens transmission-gtk, but it haults the calling program, and keeps the terminal busy till the time GUI is running.
As soon as GUI is closed, the control goes back to the program.

Is there any way that the GUI program is opened, and immediately the control returns to calling program, instead of keeping the terminal busy?

(I know transmission-remote can be used for adding torrents. Looking for a way around for transmission-gtk specifically).

Thank you!
Regards.