La Spezia, january 2nd 2013 - Police arrested a fourth man on Wednesday on suspicion of participating in the kidnapping plot of Italian construction entrepreneur Andrea Calevo, who was abducted from his home in the northwestern coastal town of Lerici on December 16.

Albanian Simon Halilaj, 23, was taken into custody by police, who said that at least seven people participated in the abduction scheme and that a total 20 suspects are being investigated. On Monday, ex-convict Pierluigi Destri was arrested along with his nephew Davide Destri based on surveillance-camera evidence that filmed Destri's car following Calevo's shortly before the abduction.

Calevo, 31, was freed by police and Carabinieri Monday from a basement belonging to one of the kidnappers in the town of Sarzana near La Spezia where he was being held.

Police said that when they rescued Calevo he was positioned in a corner of a windowless basement with his legs and arms bound.

Calevo reportedly said "thank you" to his rescuers before bursting into tears.

Calevo was abducted from his villa by armed men near La Spezia on the night of December 16 and his car, an Audi A3, was found dumped in a nearby river the following morning.

Calevo's firm, founded by his grandfather, produces prefabricated building materials and is well known in the region.

The entrepreneur told police that he was not sure he would be able to identify the kidnappers because he had been blindfolded the entire time.

"I was scared. Sometimes I heard strange movements, water running, a table move and a dog," Calevo told police.

Calevo said that he would return to work on Thursday because he could "no longer stand being home" and "felt safe thanks to the police".