06 August, 2017
Police said she was injected with an anaesthetic when she arrived at a Milan apartment, put inside a suitcase and taken in the boot of a vehicle to a village in the Piedmont region.
The Foreign Office said it was providing support to a British woman.
They said she was handcuffed to a dresser until she was released near the British consulate on 17 July - with the kidnapping suspect arrested the day after.
During her detention, Herba had demanded the model's agent pay $300,000 to avoid the model being sold online though no ransom appears to have been paid, police added.
"Fantasist or not, what is clear is that he is a very unsafe man who drugged his victim as soon as she was kidnapped and put her inside a large travel bag in the boot of a vehicle", Milan deputy prosecutor Paolo Storari told a press conference.
The woman was then kept handcuffed to a wooden chest of drawers in a bedroom for six days until she was released.More news: United Kingdom wants to ban sales of internal-combustion vehicles by 2040
Police said no one took part in auction and it was unclear if Herba was serious about the plan or whether he was a "fantasist".
He claimed he was working on behalf of the "Black Death Group", an organisation which operates in the deep web for illegal traffics, say police.
A Milan court heard the woman arrived in Milan on July 11 and was seized near the central station when she was drugged with ketamine.
The unnamed suspect faced pre-trial before magistrate Anna Magelli yesterday.
Police say they are still unclear whether the kidnappers were running an online scam to con "buyers" out of money or whether they actually meant to sell her on.
While holding her hostage, the man demanded around £45,100 (€50,000) from her if she wished to be freed.