SHANGHAI, China - Police in southern China busted a criminal ring that used a cross-border sewage pipe to smuggle mobile phones and other electronics from Hong Kong, state media reported Thursday.

Seven gang members were arrested, including the ringleader, a truck driver and five couriers who carried goods through the pipe, the official China Daily said.

Three more suspects, including two Hong Kong residents, were still being sought, it said.

The gang had dug a hole in an apartment they'd rented on the Chinese side which they then linked up to the 66-foot-long sewage pipe, the report said, citing comments by Shenzhen customs deputy director of anti-smuggling, Song Min, at a news conference Wednesday.

Police recovered about 900 mobile phones and other devices worth about $200,000, including $33,750 in unpaid taxes, Song said.

After spending about 20 days digging, the gang was only able to use the tunnel three times before being caught, Song said. He estimated the gang could have smuggled up to $75 million worth products a year had they been successful.