Azad Miah, 44, targeted his victims in what the prosecution described as a ''cold, clinical exploitation of the desperate and vulnerable''.

The married father-of-four was convicted yesterday of paying for the sexual services of two teenagers who worked in his former Spice of India restaurant in Carlisle city centre.

One of those girls was encouraged to have sex with him out of desperation for cash when she was 15, while he had a sexual relationship with the other, a heroin addict, between the ages of 15 and 17.

A jury at Carlisle Crown Court also found the Bangladeshi national guilty of inciting three other girls, one as young 12, into prostitution, while running a brothel above the shop in Botchergate.

The court heard the 12-year-old complained to police on three occasions about him persistently harassing her in 2008, three years before his eventual arrest.

She said she eventually gave up complaining because nothing was being done, although Miah's legal team said there was no official record of her complaints.

In the wake of Miah's arrest in March 2011, she was asked at the start of her police interview if she knew why she was being questioned.

She replied: ''Because of something that happened three years ago and now youse have finally decided to do summat about it.''

Police are expected to explain later today why Miah was not investigated until Christmas 2010 when one of the girls gave information to a ''partnership agency''.

In opening the case, prosecutor Tim Evans said many of the girls in the case were addicted to drugs or came from troubled backgrounds. Some were known to local care authorities.

''It is the Crown's case that the defendant deliberately targeted girls who fell into that category or who had other problems with the law,'' he said.

''The defendant believed that such girls would be more likely to give in to his persistent offers ... and they may find themselves less likely to be believed if they complained to the police against a responsible, respected restaurateur of the city.''

The girl Miah paid sex for over a three-year period showed police various locations around the city, including the entrance at Carlisle Golf Club, where he drove her.

Her drug addiction was said to have overcome her feelings about having sex with a considerably older man for £100 a time.

She also had sexual relations with three of his workers at the takeaways and said she was paid more than older prostitutes because of her age, she told the court.

The girl was introduced to Miah by the same woman who put him in touch with another 15-year-old girl who he paid £80 for sex after being told on her first day of work at the takeaway that she could make ''big money''.

She had wanted to buy drugs for her boyfriend.

The 12-year-old girl was bombarded with up to 50 texts a day from Miah who demanded sex. He told her that ''in his country it didn't matter about age''.

Prostitutes at his brothel were asked to find young girls who he described as ''fresh meat''.

The court heard that money would change hands at the shop where Miah's Bangladeshi employees and workers from other takeaways in the city were customers.

Miah was convicted unanimously of four counts of paying for the sexual services of a child between 2006 and 2009, one count of keeping a brothel between 2005 and 2011 and five counts of inciting child prostitution.

He was cleared of child prostitution allegations relating to two other girls.

Miah had denied all the charges as he claimed his accusers conspired with each other to concoct false stories because he stopped giving them money ''out of kindness''.

Judge Peter Hughes QC warned him yesterday that he faced a ''substantial'' jail term.