Yasin Bhatkal, one of the co-founders of the banned Indian Mujahideen, was arrested by Kolkata Police in 2008 in a fake currency case, but was let off.
One of the country's most-wanted men, Bhatkal was released soon.
West Bengal Police on Friday night said this is nothing new.
"This is nothing new. The whole world knows it," Joint Commissioner of Police, STF, Rajib Mishra said on Friday night when asked whether Bhatkat, a suspect in the Hyderabad serial blasts, was arrested in a fake currency case here in 2008.