Police and other criminal investigators in eastern China can tap the country’s first human body odor bank to help their dogs get a nose for criminals, Xinhua news agency said.

The facility in the city of Nanjing has a collection of 500 different smells, meant for comparison with samples taken from crime scenes. They are kept on ice – at minus 18 degrees Celsius (0 degrees F).

"This way the scent sample can maintain its freshness for at least three years," bank founder Song Zhenhua was quoted as saying.

Only odors that elicit identical reactions from at least three trained crime dogs will pass muster for a place in the bank’s vaults, Xinhua said.

Xinhua did not go into detail about how the smells would be captured or stored. In other countries that use olfactory forensic evidence, odors are taken from clothing or collected using gauze pads and airtight plastic containers.