SHIJIAZHUANG -- Twenty-two people have been prosecuted for posing as reporters and blackmailing companies in North China's Hebei province, according to local police.

Since March last year, the group had traveled to ten counties in Hebei, including the capital Shijiazhuang, Hengshui, and Cangzhou with fake journalist documents they had made or bought, according to Hengshui police.

"The suspects drove around different towns looking for smoking chimneys or companies discharging sewerage. Then they blackmailed the companies and threatened them with media exposure if they refused to pay," said Ge Tao, police officer.

The group are suspected of collecting 340,000 yuan (about $50,000) in blackmail payouts. They also blackmailed two butcheries with no environmental irregularities and collected 2,000 yuan from them, police said.

Police began the investigation after receiving information from the public last November.