Air Chief Marshal Arup Raha today described the arrest of former IAF chief S. P. Tyagi as unfortunate. Speaking to media at Kolkata Airport he said that it affects the reputation as a professional force. <br/><br/>He said he believe in the rule of law. He refused to speak further on the issue, saying the matter is sub-judice. CBI yesterday arrested Tyagi, his cousin Sanjeev, and lawyer Gautam Khaitan in the sensational Agusta Westland bribery case in procurement of 12 VVIP helicopters. <br/><br/>Our correspondent quoting CBI sources said that Tyagi was called for questioning at CBI Headquarters along with his cousin and Khaitan.<br/>