Linux – NRPE commands doesn’t work when called from remote management host

First of all: I know there were already questions about this issue, but even using their answers I still cannot figure out why my command is not working.
What I want to do is call a script on remote host using NRPE. However, this what the script is going to do may be only executed by specific user (let's call him userA).

• Now, my NRPE command looks like:

  command[debug_now]=/usr/local/bin/debug_now

• My sudoers have entry
  nagios ALL=(tomcat) NOPASSWD: /usr/local/bin/debug_now as I noticed user calling the scripts from nrpe.cfg is called nagios.

• Script /usr/local/bin/debug_now looks like:

  #!/bin/sh
  whoami
  echo "Debug..."
  sudo -u tomcat whoami
  echo "Debug finished"
  

Script above has same permissions as other scripts can be executed by user nagios. What's more, when it is executed locally it pretty prints:

nagios
Debug... 
tomcat
Debug finished

and it's generally working as intended. However, when it's called from management host, it prints only

nagios
Debug...
Debug finished

This is caused probably by NRPE: Cannot read output, which appears every time I try to sudo anything from management host. I already tried adding to sudoers entry Defaults !requiretty with no success. I use Debian 6.0.7. What can I do to make my script work, when called from management host?

EDIT.
First of all, directory /etc/sudoers.d/ contains only file README.
userA real name should be tomcat
Let's take a look at visudo output then:

 Defaults        env_reset
 Defaults !requiretty
 root    ALL=(ALL) ALL
 nagios ALL=(tomcat)     NOPASSWD: /usr/bin/whoami

 %www ALL=(ALL) NOPASSWD: /bin/su - www
 %tomcat ALL=(ALL) NOPASSWD: /bin/su - tomcat
 %tomcat ALL=(ALL) NOPASSWD: /etc/init.d/tomcat stop
 %tomcat ALL=(ALL) NOPASSWD: /etc/init.d/tomcat start
 %tomcat ALL=(ALL) NOPASSWD: /etc/init.d/tomcat restart

Please note I tried even nagios ALL=(tomcat) NOPASSWD: ALL and nagios ALL=(ALL) NOPASSWD: ALL. I also removed few user entries like username ALL=(ALL) NOPASSWD: ALL.

NRPE

 $ tail -n 1 /etc/nagios/nrpe.cfg
 command[debug_now]=/usr/local/bin/debug_now

 $ ls -l /usr/local/bin/debug_now
 -rwxr-xr-x 1 root staff 573 Dec  2 09:06 /usr/local/bin/debug_now
 $ ls -lh /usr/local | grep bin
 drwxrwsr-x  2 root      staff 4.0K Dec  2 09:12 bin
 $ ls -lh /usr | grep local
 drwxrwsr-x  14 root staff 4.0K Oct 22  2010 local

From another host

$ /usr/lib/nagios/plugins/check_nrpe -H <ip address> -c debug_now
nagios
Debug...
Debug finished