WENZHOU, Dec. 12 -- The police have arrested 52 suspects since June for illegally manufacturing and selling sexual health products, local authorities announced Friday.

The gang, who hail from south China's Guangdong Province, injected Sildenafil, the major ingredient in Viagra, into corn starch and made capsules and sold them as sexual health products, according to a police statement from the eastern city of Wenzhou, where the case was exposed.

According to law, Sildenafil is a banned health food additive, as excessive use of Sildenafil is harmful.

The illegal products were found on sale at more than 600 sex shops in 31 provinces and regions. About 12,000 boxes of these products have been seized by police.