Glamour model Chloe Ayling, 20, told reporters on the doorstep of her mother’s home in Coulsdon, south London, that during the ordeal she had no idea if she would live to tell the tale.
"I’ve been through a terrifying experience. I’ve feared for my life, second by second, minute by minute, hour by hour," she said.
“I’m incredibly grateful to the Italian and UK authorities for all they have done to secure my safe release.
“I have just arrived home after four weeks and haven’t had time to collect my thoughts. I am not at liberty to say anything further until I have been debriefed by the UK police.”
Ms Ayling gave a detailed account of the alleged abduction to Italian police.
It is believed she was drugged with horse tranquilliser ketamine, stuffed inside a bag then bundled into the boot of a car on 11 July after she was lured to Milan on the pretext of a photo shoot.
She was then said to have been kept in a house tied to furniture for six days while her alleged abductors apparently auctioned her on the dark web for £230,000.
In her statement, Ms Ayling described the moment she regained consciousness after being drugged.
“When I woke up I was wearing a pink bodysuit and the socks I am wearing now," she said.
“I realised I was in the boot of a car with my wrists and ankles handcuffed, adhesive tape on my mouth. I was inside a bag and was only able to breathe through a small hole.”
It is claimed her captors released her without harming her or receiving any payment when they learned she has a child.
Milanese police believe she was transported in the bag to Borgial, an isolated village near Turin, before being released on 17 July.
An online advert is reported to have been created using a photograph of Ms Ayling showing her curled up with a calling card on her stomach offering “sexual services” and giving her vital statistics.
Italian newspaper Il Giornale reported Ms Ayling was told she would be sold outside of Europe.
“He [one of the alleged kidnappers] told me ... That he alone had earned more than €15m (£13.5m) in the last five years and explained to me that all the girls are destined for the Arab countries,” the paper reported she said.
“When the buyer gets tired of the girl bought by auction (they) can give them to other people, and when it is no longer of interest they are to become a ‘tiger meal’.”
Black Death, the organised crime group suspected of her kidnap, claimed they released her after finding out she has a two-year-old child, Italian police said.
Investigators said they found a letter after searching a computer belonging to the gang, which read: “You are being released as a huge generosity from Black Death Group. Your release does, however, come with a warning and you should read this letter very carefully.
“You are certainly aware of your value on human slavery market and must make a note that this isn’t personal, this is business. For your release we have taken a number of factors into consideration.
“A mistake was made by capturing you, especially considering you are a young mother that should have in no circumstances be lured into kidnapping.
“Second important factor you are very well aware of is your overall protection by one of our main and very well respected men who made a very clear and solid stance in your case.
“You will, upon your landing in your home country cease any investigation activities related to your kidnapping. You also agreed to sneak a pre-determined set of information in to the media and we will expect to see evidence that has been done in the near future.
“You and your family will, in no way ever talk about us in bad language and without respect. You have been treated fairly, with respect and we expect to hear exactly the same about us in return.
“You can release any information you have heard from MO while your (sic) holding as he would never give you any information that could harm our activities.
“We will not tolerate lying about anything that has happened.
“You have also agreed to pay outstanding costs of your release of $50,000. We expect that money to be paid in BitCoins within one month.
“Any sort of disobedience with the above will result in your elimination.”
According to Ms Ayling's account to Italian investigators, she was told several potential buyers had been lined up before the kidnappers had a change of heart.
A Polish man, who lives in Britain, was arrested on 18 July on suspicion of kidnap and extortion, Italian police said.
Italian officials released a mugshot of a suspect, named as 30-year-old Lukasz Pawel Herba.
It is alleged two men tried to sell Ms Ayling online for more than £230,000 and then demanded the model's agent, Phil Green, paid £50,000 to secure her safe release.
She was taken to the British consulate in Milan, despite the ransom not being paid.
Milan police officer Lorenzo Bucossi told reporters the group the suspect allegedly worked for offered “mercenary services” on the dark web.
According to a translation on Sky News, Mr Bucossi said: “Certainly the author of this very serious crime is a dangerous person, don't forget he was also ready to carry out a 'final solution', as he called it.
”He was a killer and was working for an organisation on the deep web that is offering mercenary services such as bombing attacks, kidnapping and the selling of girls on the dark web.“
Italian police said they are working with officials in Britain and Poland as they continue to investigate.
A spokeswoman for West Midlands Police said an address in Sampson Close in Oldbury was raided on 18 July in connection with the investigation.