Trouble killing a process

[Antonia Tugores]

Hi all,

I'm having some troubles killing a process (and its subprocesses).
The process type is APR_SHELLCMD_ENV, and when I call the apr_proc_kill with 
the signal SIGABRT (with SIGKILL the results are the same), the parent 
process (sh) dies but the child (sleep) doesn't.

main_program
  /bin/sh -c ./"sleep.sh" 1 1 100  <---- dies
    ./sleep.sh 1 1 100                 <---- remains

How can I kill the process and its subprocesses?

Thank you in advance

Antonia