Two Nigerian nationals have been arrested allegedly with methaqualone, a synthetic depressant used illegally as a recreational drug, an official of the Navi Mumbai Anti Narcotics Cell said on Monday.

The two were nabbed near a mall on April 15 based on a tip-off and 258 grams of methaqualone worth Rs 25.80 lakh were seized, said Assistant Commissioner of Police (Crime) Vinayak Vast.