I tried adding to the PATH in the files ~/.profile and /etc/profile as follow.
PATH = $PATH:/required/path
I got the answer for this question in irc chat. Given here for the benefit of anyone who may come across this. Many people have given wrong answers as update the ~/.profile but that did not work. So use the answer below.
Update the file ~/.bashrc for user or update the file /etc/enviroment global for global change which will apply for all users.
In .bashrc export PATH: export PATH=$PATH:/new/path/bin
In enviroment: PATH=$PATH:/new/path/bin