The Bihar police have arrested an arms dealer, Abdul Manan, in connection with the August 25 blasts in Mumbai, sources said on Thursday.
R K Singh, district superintendent of Muzaffarpur, where Manan was held, said the police was interrogating the suspect.
He will be handed over to the Mumbai police later, the sources said.
After the blasts, a Mumbai police team had visited Bihar in search of some suspects, including Manan.
"We were looking for him as he is a notorious fugitive involved in a number of crimesÂ… he has established links with the underworld," Singh said.