BEIJING (Reuters) - A Chinese court announced on Friday it had sentenced a prominent human rights lawyer to a three year suspended jail sentence for subverting state power, after a closed-door trial.

President Xi Jinping has tightened the state’s grip on independent civil society since 2012, citing threats to national security and stability.

Li Heping, a civil rights lawyer who has previously defended practitioners of the banned Falun Gong spiritual movement, was detained along with dozens of activists and lawyers in mid-2015 during a crackdown on dissent.

As his trial touched upon state secrets, it was held behind closed doors on April 25 in the Tianjin City Number Two Intermediate People’s Court, according to a post on the court’s Weibo social media account.

The court handed down a three-year jail sentence, suspended for four years, it said, adding that Li would be stripped of his political privileges.

Patrick Poon, a Hong Kong-based China researcher for the rights group Amnesty International, said the decision to hold a closed trial raised the suspicion the allegations against him were “groundless”.

The sentence meant Li would be “silenced for another four years”, Poon told Reuters.

Li could not be reached for comment and telephone calls to the court were not answered.

Earlier on Friday, Li’s wife, Wang Qiaoling, sent rights activists videos via instant messaging platforms of men who she said had identified themselves as police and surrounded her near her home in Beijing as she was walking her dog.

They asked her to go with them to Tianjin to see Li, but she refused as they did not provide identification papers, she told Reuters.

One of them men told her he was Li’s lawyer and that Li had been convicted, which Wang said made her angry as she had not heard about the trial.

“This secret trial, no one knew it was happening, even the lawyer was provided by the state, works with the state,” she said.

“After the sentencing, he should immediately have the freedom to return home, but now they are holding him in Tianjin ... They are just using the conviction to continue to secretly lock him up,” she said.

In its ruling, the court said that since 2008, Li had used the internet and foreign media to smear and attack state organs and the legal system.

Li had also accepted foreign funds, “hyped” cases and intentionally provoked dissatisfaction with society among “some people who don’t know the fact of the matter”, the court said.

He also colluded with a small group of lawyers, “individuals engaged in illegal religious activities” and “professional petitioners” to attack the constitutionally based system, the court said in its ruling.

The court said in its statement that Li would not appeal and had thanked the court after proceedings concluded, expressing regret and saying his behavior had broken criminal law.

The court ruled that Li’s “relatively small” number of crimes and his expression of regret meant he was given the suspended sentence.