An Italian court on Monday found a Polish man guilty of kidnapping British model Chloe Ayling in July 2017.
Ms Ayling said she feared for her life during her six-day ordeal and that she was told she would be killed if she did not co-operate.
Italian police said the brothers were members of a group called the Black Death, which tries to sell women on the dark web as sex slaves. Herba said he was in love with her and they came up with this abduction scheme together to help with her financial difficulties.
Lukasz Herba sits beside his lawyer in court.
Lukasz Herba, 30, was jailed for 16 years and nine months at the Milan court.
He also said Ayling was considering possible civil action in British courts against media that accused her of lying about being a victim to become famous.More news: Italian military ships to escort ‘Aquarius’ to Spanish port of Valencia
He had claimed she went with him willingly, which she denied.
Mr Sington said: "Let's not forget she was bundled into a suitcase, injected with ketamine in the boot of a vehicle, and thought she was going to die".
She was taken to a remote mountain village where she was kept for nearly a week before Herba drove her back to Milan and released her near the British consulate.
"It's hard if you're being painted as a liar and now she's able to say, "I know it's a freakish story but it's a true one". "But it certainly was not as Chloe has described".
Herba told the court: "I was in love and I was hoping once her fame took off she would repay me with feelings and we would share the money".
Defendant Herba, 30, had claimed Ms Ayling agreed to the scheme to boost her career.More news: Intel's First Dedicated Graphics Cards to Launch in 2020
The young model told police she never tried to escape, even when she accompanied her kidnapper into a shoe store, because she was terrified and believed his threats that he was part of a bigger criminal gang.
His brother, Michal Herba, was arrested in the Tividale area of Sandwell, West Midlands, in August and was ordered to be extradited to face trial in Italy.
During closing arguments, his lawyer, Katia Kolakowska, cited an email she received from a United States film producer, who pointed out that Ayling's story closely matches the plot of a movie titled By Any Means that was released about eight weeks before the 2017 kidnapping.
The prosecutor also cited Herba's purchase of two ski masks, which Chloe said she saw kidnappers wearing when she was freed from the canvas bag, and the exchange of notes with his brother about cleaning the auto trunk well to make sure there were no traces of her hair.
"Let´s not forget she was bundled into a suitcase, injected with ketamine in the boot of a auto and thought she was going to die", Sington added.
Ayling's agent Adrian Sington said the ruling was vindication for his client. "It's hard if you're being painted in the press as a liar, and now she's able to say, 'I know it's a freaky story, but it's a true one'".More news: Portugal cliff deaths: Victims identified as Perth couple