By Hugh Schofield BBC correspondent in Paris

Police have launched a manhunt for Fernandez Iradi

A man believed to be a senior member of the Basque separatist group ETA has escaped from police custody in southern France.

Ibon Fernandez Iradi extricated himself from police headquarters in the town of Bayonne near the Spanish border early on Sunday morning.

Fernandez Iradi was arrested on Thursday in what was seen as an important coup for police tracking ETA on either side of the Spanish border.

He and a woman were driving a car with false number plates.

Their detention led to seven more arrests of people Spain has recognised as ETA operatives living in hiding in France.

Manhunt

Fernandez Iradi is believed to be a logistics chief, responsible for organising the backup for teams who carry out attacks across the border.

ETA has killed more than 800 people

His escape is a severe embarrassment for the French.

They have launched a manhunt across the south western corner of the country.

It comes four months after another ETA detainee walked free from a prison in central Paris.

His brother, who resembled him, succeeded in swapping positions during a family visit.