The former India captain was tested by the NADA in March and his 'A' sample tested positive for Terbutaline, a prohibited substance on the World Anti-Doping Agency list. Paul did not apply for a Therapeutic Use Exemption.
"The substance does not require immediate suspension and the athlete is free to play till the panel makes a decision," NADA chief Navin Agarwal said.
Paul did not exercise his right to get his 'B' sample tested and is free to play as the substance features in the specified list of banned substances.
He blamed a cough syrup for the positive test, according to local media.
"As soon as he makes his submission, the panel will set a date for hearing," Agarwal added.
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.
India, who have climbed to 100 in FIFA rankings, play a friendly against Lebanon on June 7 and the 2019 Asian Cup qualifier against Kyrgyzstan on June 13.
Image: Subrata Paul
Photograph: Ahmed Jadallah/Reuters