Police have arrested a 20-year-old asylum seeker and three youths for gang-raping a Polish tourist on an Italian beach as her badly beaten husband was forced to watch.

The Congolese national was arrested on a train between Milan and Pesaro a week after a woman was attacked by a group of men on Rimini beach in the country's north east.

Two brothers aged 15 and 17 and another 16-year-old have also been detained over the 'brutal and bestial' rape on the Adriatic coast.

A 26-year-old Polish woman was repeatedly raped by a group of men on Italy's popular Rimini beach, police say. Pictured above, Italian Scientific Police investigate the site of the incident

Police have arrested (pictured) a 20-year-old asylum seeker and three youths for gang-raping a Polish tourist on an Italian beach as her badly beaten husband was forced to watch

The 26-year-old Polish woman was repeatedly raped in front of her husband who was beaten and robbed by the same group of men on the beach, police say.

Her partner, also 26, passed out after being beaten on the head and robbed, reports said.

The Poles were hospitalised with injuries after passersby saw the couple, bloodied and dazed, on the beach.

The 26-year-old Polish woman was repeatedly raped in front of her husband who was beaten and robbed by the same group of men on the beach, police say

According to police the same gang of men then raped a transgender woman in a park

According to police the same gang of men then raped a transgender woman in a park.

The Congolese suspect, who arrived in Italy in 2015, was arrested by two female police officers.

He had been granted permission to stay in Italy until 2018 on humanitarian grounds following the rejection of his bid for asylum, Italian media reported.

The arrested brothers are said to have handed themselves into police after their father recognised them on CCTV images shared by police and told them to report themselves, The Local reports.

The 16-year-old suspect was held in a town nearby.