Paris - The alleged head of the military wing of the Basque separatist group ETA has been placed under investigation by a Paris court on charges of terrorism, French radio reported on Friday.

The step initiates a judicial phase that could end with Mikel Garikoitz Aspiazu Rubina being tried on several charges, including leading a terrorist group and possession of stolen goods.

If convicted on the charges, the man also known as Txeroki faces a maximum sentence of 20 years in prison.

Although he is also suspected of gunning down two Spanish police officers in south-western France in December 2007, he was not charged with the crime because of lack of evidence.

The 35-year-old Txeroki was arrested on Monday near the French Pyrenees ski resort of Cauterets, in a coordinated operation between French and Spanish security forces.

Spanish Prime Minister Jose Luis Rodriguez Zapatero hailed the arrest as a "determining" blow to ETA, which as a result "is weaker today." (dpa)