Greek lawmakers will investigate whether politicians were involved in allegedly corrupt deals between the Greek state and German industrial giant Siemens AG.

Parliament unanimously accepted a proposal Wednesday by 128 governing Socialist deputies for a probe which will include claims political parties received cash from Siemens slush funds.

Last year, the previous conservative majority rejected a similar investigation.

Greek judicial authorities are probing claims that Siemens paid bribes to secure telecoms and security contracts before the 2004 Athens Olympics.

Twenty people have been charged with bribery and money laundering so far, including several former executives at Siemens' Greek branch and a former Socialist lawmaker. All deny wrongdoing.