The European Commission's top justice official is seeking extra explanation from France on its policy towards Roma before pronouncing on the expulsions under way, an EU official said Wednesday.

Commissioner Viviane Reding said in report presented Wednesday that "the commission is waiting for detailed information from France," the official who had seen the document told AFP.

The "clinically neutral" report recalled European Union rules on the freedom of movement and freedom of establishment, said the official on condition of anonymity.

Article 21 of the Treaty of Rome says that all EU citizens have the right to move and establish themselves in any of the 27 member states.

However restrictions may be imposed in the name of "public order, public security or public health".

Reding's report also reproduces her statement on August 25 when she expressed "some concern" about the French policy towards the Roma Gypsies, the official said.

"At this stage, the commission is still lacking some information," before it can pronounce on the legality of the expulsions, the official told AFP.

France has linked the Roma to crime and expelled nearly 1,000 to Romania and Bulgaria since announcing a high-profile crackdown last July, sparking international criticism and warnings of xenophobia.

French Immigration Minister Eric Besson and European Affairs Minister Pierre Lellouche travelled to Brussels to explain the controversial measures, defending the deportations on Tuesday as being in line with EU laws.