Immigration officers picked up another seven Chinese nationals seeking to use Bermuda as a backdoor to the States on Thursday.

It is the third case this year in which migrants from China or Singapore have attempted to pass through using false passports.

Home Affairs Minister Randy Horton said the seven arrived from London on Thursday evening. Three were using false Japanese passports and were put back on the plane.

He said: "All three were identified as false and of the same type as used in previous incidents. "The other four were travelling on South Korean passports which at first appeared to be genuine.

"However the immigration officers were not completely satisfied and asked for the assistance of US immigration experts who determined the passports were genuine but all four had been stolen.

"Those investigations took a considerable amount of time. They were not completed before the British Airways return flight to Gatwick had departed.

"Consequently the four passengers had to be taken into custody to await departure of the next available flight to London."

Chief Immigration Officer Martin Brewer said this week that migrants have told officials that Bermuda is considered a "soft target for access to North America."

Asked about this Mr. Horton said: "We had seven people trying to get through but they were not able to get through which says we in immigration have our eye on the ball."

Immigration officials began double checking all Japanese passports after finding travellers holding the false documents twice this year.

Last month authorities detained two Chinese migrants and in January they held three from China and one from Singapore - all of whom were found holding false Japanese passports.