A niche UK smoked fish producer said it's the first to offer land-based salmon onto the UK market.

London-based Secret Smokehouse said the new products are sourced from a flow-through system.

Unlike recirculating aquaculture system (RAS) land-based salmon farms, which are fully closed, flow-through systems bring seawater into the system for recirculation.

Secret Smokehouse Managing Director Max Bergius told IntraFish the products have already sold out.

"[There is a] big demand for such a product with our clients and customers, who are very well informed," Bergius said.