China is preventing the family members of suspected fugitives, including foreign nationals, from leaving the country in order to force alleged criminals to return and face charges.

Among those are Americans Sandra Han and her two adult children, Victor and Cynthia Liu. Ms Han’s husband, Liu Changming, a former executive at a state-owned bank, stands accused of being at the centre of one of China’s largest bank frauds, totalling £1 billion.

Ms Han is being held in a secret jail, and her children have not been allowed to leave China since arriving this summer to visit a sick relative, according to the New York Times. By holding them hostage, Chinese authorities are hoping to flush out Mr Liu and to force him to return to China to face charges.

Since coming to power in 2012, Xi Jinping, China’s president, has waged a brutal anti-corruption crackdown, a campaign critics say is about shooting down political enemies. About 1.5 million government officials have been punished for wrongdoing and dramatic stings have uncovered piles of hidden cash.

In 2015, authorities launched “Operation Skynet,” which targeted former officials suspected of fleeing the country with illicit gains. That same year, Interpol issued a “red notice” for Mr Liu, one of the names on the “Skynet” list. His whereabouts remain unknown, and is reportedly no longer in touch with his now detained family members.