British police have arrested the brother of a man suspected of abducting a British model in Milan and threatening to auction her online unless a ransom was paid.
Model Chloe Ayling told Italian police she had been held captive for six days after being lured to a photo shoot in Italy last month where she was kidnapped.
Italian police said they had arrested the alleged kidnapper, Lukasz Pawel Herba, a British resident born in Poland, and he had confessed to being involved in a plot.
Britain's National Crime Agency said on Wednesday officers had detained his brother, Michal Konrad Herba, 36, in the Tividale area of Birmingham, central England on a European arrest warrant issued by Italian authorities.
He is due to appear at London's Westminster Magistrates Court on August 17.
Ayling told police that when she arrived at the studio for the Milan photo shoot, she was drugged, gagged, bound, stuffed into a bag, put into the boot of a car and driven to a village near Turin, in northwest Italy.
Her lawyer said the plot was to sell the model for sex in an online auction unless a $US300,000 ($A380,790) ransom was paid.
Lukasz Herba told police he freed her and handed her to the British consulate after the group became aware she had a young child, according to documents outlining his testimony.
Ayling has given a number of TV and press interviews since returning to Britain to give details of her abduction and respond to critics who have voiced doubts about its veracity.
