A petition challenging M Nageswara Rao's appointment as the interim chief of the Central Bureau of Investigation (CBI) is likely to be heard by the Supreme Court next week. Mr Rao took over the top job last Friday after Alok Verma was sacked as the chief the agency by a high-powered panel headed by Prime Minister Narendra Modi. Mr Rao promptly reversed all decisions taken in the previous two days by his then boss. He has also started the process of making structural changes in the CBI to streamline the workload on various zones of the agency across the country, officials said.