Warsaw  - The head of the Polish Social Insurance Institution (ZUS) was charged with taking bribes, including building materials, vacations, prosecutors said Monday in Szczecin, northwest Poland.

Sylwester Rypinski, the head of ZUS, was detained last week on six corruption charges after the Internal Security Agency entered ZUS headquarters in Warsaw. Four others were also arrested

Rypinski was charged with accepting some 21,000 zloty (7,281 dollars) worth of building materials and services for work on his home. He also accepted sea vacations and payments for the cost of transporting a car from abroad and related taxes, authorities said.

Authorities were tipped to the alleged wrongdoing in May 2008, when a Szczecin businessman told them that local ZUS workers made him an offer of a corrupt nature.

Investigations, launched a month later, included 180 officials from the Internal Security Agency, who questioned 80 witnesses and conducted 34 searches.

Also arrested on corruption charges were the head of ZUS in Szczecin, another high-ranking ZUS employee and a local businessmen. The vice-head of the Szczecin ZUS was detained but later released.

Rypinski faces up to 10 years in prison on the charges. (dpa)