HUAIROU (REUTERS) - A Chinese court on Sunday sentenced the brother-in-law of jailed Nobel Peace Prize laureate Liu Xiaobo to 11 years in prison on charges of fraud in a case that rights activists have called another example of official retribution on the Liu family.

Supporters of Liu Hui say his case was trumped up, aimed at thwarting the increasing attention by the rights community on the plight of Madam Liu Xia, who has remained under house arrest since her husband Liu Xiaobo won the Nobel Prize in 2010.

The court in Huairou, a one-hour drive northeast of Beijing, convicted Liu Hui, a manager in a real estate company in the southern city of Shenzhen, on charges of defrauding a man called Zhang Bing of 3 million yuan (S$610,860) with another colleague, lawyer Mo Shaoping told reporters.

Liu Hui has maintained his innocence, according to his lawyers.

Liu Hui was out on bail last September, but then arrested again in January, after several rights activists and foreign reporters forced their way past security guards late last year to visit Madam Liu, one of his lawyers, Shang Baojun, told Reuters before the verdict.

Liu Xiaobo, a veteran dissident involved in the 1989 Tiananmen Square pro-democracy protests crushed by the Chinese army, was jailed for 11 years in 2009 on subversion charges for organising a petition urging the overthrow of one-party rule. His wife is rarely allowed out and is almost never allowed to receive visitors. She has not been convicted of any crime.