TV channels showed a man throwing black ink at the forehead of Roy.
The attacker has been identified as Manoj Sharma from Gwalior. Following the commotion, the court has been locked, restricting public entry.
After throwing black ink at Roy, he told media persons that he is an advocate and an activists who is fighting against corruption.
The attacker also accused Roy of stealing money of poor people.
The attacker was also allegedly 'manhandled' by few supporters of Subrata Roy. He has been detained and taken to Tilak Marg police station.
Meanwhile, Roy has 'promised' to speak to media once he is out of the court.
Roy is scheduled to be produced before the apex court at 2 pm today. The SC had issued a non-bailable warrant against him in a case of alleged contempt.65-year-old Roy surrendered on last Friday and was arrested by the UP police which he had evaded for two days.
The Sahara chief was lodged in a guest house of the state forest department at Kukrail after the state police was directed by a local court on February 28 to keep him in its custody till March 4 when he will be produced before the Supreme Court.
The order to arrest Roy was issued on February 26 for his failure to appear before the apex court in a contempt case arising out of non refund of Rs 20,000 crore to investors by two of his companies.