A member of a German neo-nazi gang has been jailed for life for her part in the murders of ten people during a seven-year campaign of racially-motivated violence.

Beate Zschaepe, 43, showed no reaction as the judge read out her sentence at the end of one of the most closely watched court cases in Germany's post-war history.

She was part of the National Socialist Underground, whose members killed eight Turks, a Greek man and a German policewoman between 2000 and 2007, the Higher Regional Court in Munich ruled.

The judges said Zschaepe bore "particularly heavy guilt" and handed her the heaviest possible sentence.

She had denied any knowledge of the murders during the five-year trial.

But she later said that she regretted not stopping two male members of the gang, Uwe Boehnhardt and Uwe Mundlos, from carrying out the killings.

Those men killed themselves in 2011 when police discovered the gang by chance.

Prosecutors said Zschaepe had played a key role behind the scenes, planning the crimes and arranging money and alibis.

Five of the ten murders took place in Bavaria, the most violent attacks of their kind in Germany since the far-left Red Army Faction's two-decade killing spree that ended in 1991 and left at least 34 dead.

Zschaepe was also found guilty of membership of a terrorist organisation, of being co-perpetrator in two bombings, and of arson.

Four men were convicted of supporting the NSU in various ways, including procuring weapons, and handed sentences of between two-and-a-half and ten years.

A group of people in the court applauded when one of the men received a lower sentence than expected.

Zschaepe's lawyer, Mathias Grasel, said he would appeal against the ruling.

A report found that police had "massively underestimated" the risk of far-right violence and that missteps had allowed the cell to go undetected.

"This is a just punishment for the NSU's cold-blooded and unprecedented series of crimes," Bavarian Interior Minister Joachim Herrmann said in a statement.

"What the perpetrators did cannot be made up for. The victims will never be forgotten," said German Foreign Minister Heiko Maas.

He said Germany needed to tackle racist violence with diversity and the strength of law.

Turkey's foreign ministry said the trial had not uncovered the full story of the murder of its citizens and the other victims.