Suspected illegal immigrants have been questioned by police after an investigation into human traffickers known as Snakeheads.

Five Chinese men, all aged in their 20s, were arrested at an address in central Liverpool.

On Wednesday they were being questioned by detectives and immigration officials at a police station on Merseyside.

A sixth man was released without charge.

High fees

A spokeswoman for Merseyside Police said: "We are investigating links to organised gangs of people smugglers known as the Snakeheads. The inquiry is ongoing."

Snakeheads are Chinese gangsters who charge the migrants a reported �16,000 to be smuggled into Europe.

They often allow desperate people to borrow the cash at extortionate rates of interest.

They are usually then forced into slave labour or prostitution to pay off the debt when they reach their destination.

Snakeheads are reported to have organised the smuggling operation in which 58 illegal immigrants suffocated in the back of a lorry during a ferry crossing from Holland to the UK in July 2000.