"Run-away" MATLAB in linux

Hi,
launch MAtlab from a linux script file:

#!/bin/sh
/usr/bin/setsid /usr/local/bin/matlab -desktop

Close matlab and there is still a matlab process running in
background, even though all matlab processes are closed, as confirmed
by top

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
4269 rodgers 25 0 424m 127m 51m R 96 6.3 3:47.55 MATLAB

How can I close this "run-away" matlab process?
.