A Vietnamese gang used two houses to grow cannabis worth more than £70,000.

Police discovered one cannabis factory above a hairdressers in Brighton after a tip-off, a court heard.

They were alerted by neighbours who feared someone had died because of a strange smell coming from the flat in Upper Bevendean Avenue.

Inside, they found up to 600 mature plants and seedlings being grown to produce skunk cannabis.

Alan Kent, prosecuting, said four members of the gang were arrested after police kept watch on the flat last October.

Electricity meters had been altered to power hydroponics equipment used to grow the plants.

Lists of chemicals, a cultivation magazine and a Tropical Growers business card were found during searches, Hove Crown Court was told.

The flat had been rented by Tam Hoang who tended the plants with boyfriend Ken Dinh.

Mr Kent said: "They were living there as a couple to give an appearance of respectability and avoid raising suspicion."

A call received on Dinh's mobile phone after his arrest was traced to a phone box in Queen's Road, Brighton.

Detectives kept watch on a second Vietnamese couple seen in a nearby sandwich bar.

The woman went into a nail bar in Queen's Road while the man, Van Hoang, waited outside. Both were arrested.

Police searched the nail bar and documents were found linking it to the Upper Bevendean Avenue cannabis factory.

A letter was also found from a friend of teachers Tony and Natalie Webster who had moved abroad.

It asked her to send them visa documents stored in the loft of their home in Crown Road, Portslade.

Police contacted her and she took them in February to the house where another 196 cannabis plants were found.

All the plants had died from neglect because the people tending them were already under arrest, the court heard.

The Websters had rented their house to Tam Houang, who called herself Anna Hu, before they took up teaching jobs in Thailand.

Thousands of pounds of damage had been done to the Websters' home when it was converted into a cannabis farm.

Mr Kent said: "They are now living in Hong Kong and the cost of repairs and travel expenses involved in dealing with this amounts to more than £11,000."

Hoa Tran, 30, Quen Can, 21, Van Hoang, 37, Tam Hoang, 32, and Kien Dinh, 33, were all Vietnamese nationals who had come to Brighton and Hove from London.

They had denied being involved in the cultivation of cannabis but changed their pleas to guilty before the start of the trial on Tuesday.

Jeffrey Lamb, defending Tran, said he had payed £12,000 to be smuggled into Britain in the back of a lorry.

Mr Lamb said: "He had a minimal part and was involved solely as a plant sitter."

Jeremy Wainwright, for Van Hoang, said: "He was asked to do some work at the Portslade house by another man.

"His role was to set up the equipment but he was not involved as an organiser."

Nicholas Hamblin said Tam Hoang had come to Britain in 1991 after living in refugee camps in Hong Kong.

He said: "She was asked to rent the houses by a man called Dung who said they were for hotel workers to live in."

The court heard that none of the defendants had previous convictions.

Tam Hoang was jailed for 27 months, Tran for 20 months, and Can, Dinh and Van Hoang for 18 months.

Judge Charles Kemp told them: "I am certain the sale of such quantities of cannabis would have resulted in considerable sums of money for you.

"The cultivation of cannabis is regarded by the courts as a serious criminal offence.

"By the time of these events cannabis had been downgraded to a Class C drug. It is, nonetheless, still a controlled drug and in the hands of the wrong person can be a dangerous.

"As the courts know too well, it can often be the stepping stone to harder drugs."

The sentences were welcomed by Brighton and Hove police commander Chief Superintendent Kevin Moore.

He said: "Sussex Police have been targeting cannabis factories across the county. An unprecedented number have been uncovered and a number of people arrested.

"Today's sentences send out a strong message - you are not welcome in Brighton and Hove. We will track you down."