Kidnapped model Chloe Ayling's lawyer says she only "went along with" her captors to keep herself alive.

A British model who was allegedly kidnapped in Milan was too terrified to try to get away from her captor when he took her shoe shopping and to buy groceries, her lawyer said.

Italian police said Chloe Ayling was snatched last month by a group calling itself Black Death and is believed to have been drugged and transported in a bag to an isolated village near Turin, where she was held for six days as her captors tried to auction her online.

The 20-year-old was told people were watching her and she would be killed if she tried to flee, meaning she complied with what her captor asked her to do, her lawyer Francesco Pesce said.

“She was told that she was going to be sold to somebody in the Middle East for sex,” he told Radio 4.

“She was told that people were there watching her and ready to kill her if she tried anything.

“So she thought that the best idea was to go along with it and to be nice in a way to her captor because he told her that he wanted to release her somehow and some time and she thought that the best thing to do was not to go in conflict with him.

“So she abided to his request, ‘let’s go and buy groceries’ and ‘you need shoes, let’s go buy shoes’ and she didn’t try to flee.

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“But I believe she was terrified at the moment and even if she could’ve asked for help she didn’t because she was subjugated to this person, or people as she was given to understand.”

The Sun reported she told police she had developed a trusting relationship and even shared a bed with her kidnapper, who gave her chocolate and underwear, but she said he had not sexually assaulted her.

There was no sign of Ayling at her terraced home in Coulsdon, south London, on Monday.

“I’ve been through a terrifying experience. I feared for my life, second by second, minute by minute, hour by hour,” she said.

“I am incredibly grateful to the Italian and UK authorities for all they have done to secure my safe release.”

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A Polish man who lives in Britain was arrested on July 18 on suspicion of kidnap and extortion, state police said.

Officials released a mugshot of the suspect, named as 30-year-old Lukasz Pawel Herba.

The UK’s National Crime Agency said it has been assisting with the investigation.

It’s alleged the men tried to sell Ayling online for more than $US300,000 ($A378,780) and demanded the model’s agent pay to secure her release.

She was kept handcuffed to furniture in the village of Borgial but was freed after six days and taken to the British Consulate in Milan, despite the ransom not being paid, police said.