In the first case of corruption charge against Andhra Pradesh Chief Minister N. Chandrababu Naidu, a court today asked the Anti-Corruption Bureau (ACB) to investigate a complaint against him, former Excise minister T. Nageshwar Rao and 12 others about alleged irregularities in purchase of liquor by state-owned Beverages Corporation.Based on a complaint by N. Krishna Kumar Goud, a Congress functionary, the Principal Special Judge for ACB cases S. Ananthasayana Prasad directed the ACB Director General to probe the charge that ‘‘excess amount to the tune of Rs 550 crore’’ was paid to some distilleries in the purchase of liquor between 1997 and 2000.Seeking action under the Prevention of Corruption Act, Goud, who is the joint convenor of APCC legal cell, filed a complaint before the Special Court yesterday alleging that Beverages Corporation had purchased liquor from some leading distilleries at a rate almost double than those prevailing in Tamil Nadu and Karnataka.