In a notice earlier this week, CPCB Chairperson S P Singh Parihar asked the police commissioner to ensure the court order on burning green firecrackers for a stipulated period of two hours is complied with.
The court had directed that bursting of crackers on Diwali and other festivals be limited to two hours and only "green firecrackers" be sold in Delhi and the National Capital Region.
However, gross violations of the order were observed during Diwali with rampant burning of toxic firecrackers across the country.
The CPCB on November 9 sought an explanation from the police commissioner on violations of the apex court order.
It said it has received a response from the police commissioner on its notice issued on November 9, in which the Delhi police said no temporary license was issued and inspection of premises of all 18 license holders was carried out and show-cause notices were issued against two of them.
The Delhi police also informed the CPCB that for violating the apex court directions, as many as 613 people have been arrested and 8,286 kg of explosives seized.
A thick haze had engulfed Delhi the morning after Diwali as the city recorded its worst air quality of the year. The pollution level in the national capital had entered the "severe-plus emergency" category or 10 times the permissible limit.
The CPCB has sought reports on the issue by January 7.