A Chinese court sentenced disabled activist Ni Yulan and her husband to jail for "provoking trouble" on Tuesday, a year after the couple were detained during a widespread crackdown on dissent.

Ni, who has used a wheelchair since 2002, was sentenced to two years and eight months on separate charges of fraud and "picking quarrels, provoking trouble and wilfully destroying private and public property".

Her husband Dong Jiqin was jailed for two years on the latter charge, a court spokesman told gathered media and foreign diplomats outside the Beijing courthouse, where around 100 police officers were deployed.

"This is completely unfair, I urge the government to release my parents," the couple's daughter Dong Xuan told AFP after the verdict and sentencing.

"Both my parents looked very thin. I was unable to see my mother's face, she didn't turn around. She was in a wheelchair and looked very weak. My father saw me and asked me how I was. He told me that he was ok."

Ni and Dong, who have long helped victims of government-backed land grabs in China, were detained in April last year as authorities rounded up scores of activists amid online calls for protests similar to those in the Arab world.

They were tried in December in a four-hour hearing that was closed to the press and diplomats who tried to enter the courthouse. Their lawyers say the charges were trumped up to silence them.

"We believe this verdict is unfair and a violation of the law," lawyer Cheng Hai told journalists following the sentencing.

"During our defence we said that this case was not a criminal case, but a civil dispute, it should have been handled differently... this just reflects the state of China's judicial system."

Cheng said Ni and Dong's conviction stemmed from their refusal to pay a 69,000 yuan ($11,000) bill for a hotel where police placed them in June 2010, after Ni was released from her previous two-year jail sentence.

The couple had been living on the streets after their central Beijing home was demolished after a long legal battle in November 2008.

Ni was also convicted of fraud, Cheng said, but the alleged victim did not appear as a witness at the trial and defence attorneys were unable to locate and question the person.

Ni spent the December trial lying on a bed in the courtroom due to her poor health. She remains ill and is suffering from fever, a swollen neck and has trouble speaking.

Ni's case has been championed by numerous Western governments, including the United States and the European Union, which sent representatives to meet with her during her brief period of freedom in 2010.

In January, police barred Ni's daughter Dong Xuan from leaving China to collect a 100,000-euro ($131,000) human rights award for her mother in the Netherlands.

After Tuesday's sentencing, the EU delegation in China called for her immediate release, saying it was "deeply concerned" by the sentencing, and by Ni's poor health.

Trained as a lawyer, Ni, 51, was sentenced to a year in jail in 2002 for "obstructing official business" and for two years in 2008 for "harming public property" -- charges brought against her as she tried to protect her home.

Amnesty International has said her knee caps and feet were broken when she was detained in 2002, and she has been confined to a wheelchair ever since.

She was also disbarred in 2002.

The international director of pressure group Chinese Human Rights Defenders, Renee Xia, also condemned the sentencing.

"By handing down this verdict to punish human rights activist Ni Yulan, who suffered from torture that left her paralysed during previous imprisonment, the Chinese government tells the world defiantly that it has nothing but disdain for human rights," she said.

Government-backed land grabs are a hugely contentious issue in China, frequently triggering protests as residents complain of poor compensation for homes that have been demolished to make way for new buildings.

New rules were issued last year stipulating that violence cannot be used to force homeowners to leave and that compensation must not be lower than the market price, but these regulations are often flouted.