An Eta terrorist serving a 13-year jail term has been released for IVF treatment, causing outrage among victims of the Basque separatist group.

Six months after Elena Beloki, 47, was sent to prison she was released so that she could begin the fertility treatment in June.

After her first attempt a judge ruled that she could remain on conditional bail until the in vitro fertilisation course was completed. She was unable to have a baby through natural methods and sought to try IVF, which is being paid for by the Spanish State.

The judge's decision has angered members of the Association of Victims of Terrorism (AVT), who say there is a danger that she will return to Eta. The prosecutor in the case also opposed her bail and doctors said that she could have received the treatment behind bars.

Beloki was sentenced to 13 years in jail in December for being a spokeswoman for Xaki, the international arm of the banned Basque group. In June she was released after asking to have a course of IVF treatment, claiming that it was her last chance to become pregnant. Her boyfriend is Juan María Olano, a jailed leader of Euskal Herritarrok, a banned political party linked to Eta.

After the half-hour treatment, Beloki was granted permission by a court to remain on conditional bail.

The AVT, which supports victims of Eta attacks, made a formal complaint to the court, claiming there was a real risk that Beloki would flee or once again become involved with Eta. But Judge Alfonso Guevara ruled that she should remain on bail with a surety of €3,000 (£2,330) until the treatment was completed. He said that she continued to comply with her bail conditions and was not considered a flight risk or deemed likely to reoffend.

After the ruling Teresa Jiménez-Becerril, the sister of the councillor Alberto Jiménez-Becerril, who was assassinated by Eta in 1998, said that the release of Beloki was “another slap in the face for the victims”.

The latest ruling has angered victims, who are calling for more stringent controls on those convicted of terrorism in Spain.

In August there was an outcry after the country's most notorious terrorist, Iñaki de Juana Chaos, was released from prison having served 21 years of a 3,000 year sentence for the murder of 25 people in a series of attacks in the 1980s. De Juana, 52, said that he planned to live on a street in San Sebastián, in the Basque Country, where three women widowed by Eta violence live.

The Spanish Government has said that it will try to prevent freed Eta terrorists from living close to victims. A Spanish judge has requested help from Interpol to find de Juana and return him to Spain, where he is wanted in connection with a complaint accusing him of “glorifying terrorism”.

Eta has killed more than 850 people in its 40-year fight for an independent Basque homeland.

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