ISLAMABAD - The top hierarchy of National Accountability Bureau has started consulting legal and constitutional experts to seek guidance on whether the department should take up the extension cases of people holding key positions in government, including the chief of the army staff and the Supreme Court of Registrar, who have attained the age of superannuation.Sources aware of the development taking place on this front told The Nation that the partial application of the law by the NAB authorities came under severe criticism at some top government meetings and the message was conveyed to the authorities concerned after which it was decided that the NAB should act against those on top government slots, who have attained the age of superannuation as was done in the case of Tauqir Sadiq and others.When contacted, the NAB spokesman expressed his ignorance about such a development, but sources insisted that the NAB legal wing was consulting top legal and constitutional brains in the country to have their opinion whether NAB could set the law in motion against such persons, including the chief of army staff and the Supreme Court of Pakistan registrar, who have attained the age of retirement, but are working on extension in service granted to them by the competent authority.It is pertinent to mention here that a retired colonel, Inamur Rahim, has already challenged the extension granted to Chief of Army Staff Gen Ashfaq Parvez Kayani in the Islamabad High Court wherein the petitioner has taken the plea that the army chief has crossed the age of superannuation and under the Supreme Court of Pakistan judgment, such a government servant cannot stay in service.Similarly, Supreme Court o Registrar Dr Faqir Hussain has also crossed the retirement age of 60, but is still in service on extension.