Caches of arms were found at two different locations across the city on a day when Union home minister Amit Shah was present in the city.
Shah is on a three-day trip to Calcutta starting Monday.
Police said one cache was found in Alipore, while the other was on Strand Road on Tuesday.
Kolkata Police officers dug up an isolated land off Orphangunge Road near the Alipore zoo and found 11 guns hidden underground on Tuesday morning.
The police named BJP leader Rakesh Singh as the mastermind of hiding these arms.
“We had information from sources that arms were hidden near Orhangunge Road. Around 3.45am, the arms were found in an isolated place behind a temple on Orphangunge Road,” said deputy commissioner (south division), Kolkata Police, Priyabrata Roy on Tuesday.
One person has been arrested for the illegal possession of arms. “During preliminary investigation, it was found that Rakesh Singh had asked the accused to hide these arms behind the temple,” said Roy.
Singh, a BJP leader, is already in custody for a separate case.
The police said his name would be mentioned in the FIR related to this case for illegal possession of arms.
In a separate raid conducted by the Special Task Force of Kolkata Police, three more arms were found in possession of two men who were picked up from Strand Road.
“Rabindra Prasad, 32, and Jitendra Prasad, 29, are brothers. They are from Fakir Bagan Lane, Pilkhana, in Howrah Salkia. They were detained near Strand Road and later arrested as they failed to provide any documents for carrying the arms,” said additional commissioner (Special Task Force), V. Solomon Nesakumar.