NEW DELHI, April 25 (Reuters) - India goalkeeper Subrata Paul has tested positive for a banned substance, the All India Football Federation (AIFF) said on Tuesday. "His sample A has tested positive," AIFF secretary Kushal Das told Reuters. National Anti-Doping Agency chief Navin Agarwal confirmed the former India captain was tested by NADA officials in March but declined to elaborate further. The 30-year-old was India's number one choice under the bar before slipping down the pecking order, behind Norway-based Gurpreet Singh Sandhu, in recent times. Paul did not take calls when Reuters contacted him. "It's now between him and NADA. He has to decide whether he wants his B sample tested," Das said. "But of course if he needs guidance, the federation is always there." (Reporting by Amlan Chakraborty in New Delhi; editing by Sudipto Ganguly)