Stepping up his attack against the government, Congress President Rahul Gandhi on Friday alleged that it was "inconceivable" that the CBI, which reports to Prime Minister Narendra Modi, would have diluted without his approval the look out notice against fugitive liquor baron Vijay Mallya."Mallya's great escape was aided by the CBI quietly changing the "detain" notice for him, to "inform". The CBI reports directly to the Prime Minister. It is inconceivable that the CBI, in such a high profile, controversial case, would change a lookout notice without the approval of the Prime Minister," Gandhi tweeted.His remarks came a day after he accused Union Finance Minister Arun Jaitley of "colluding" with Mallya to help him flee the country and demanded his resignation.He asked why had Jaitley not informed the investigative agencies about his meeting with the chief of now-defunct Kingfisher Airlines.Mallya, who left India on March 2, 2016, faces charges of defrauding banks to the tune of Rs 9,000 crore.