The Intermediate People's Court of Tianjin handed down the sentence in a closed-door trial over corruption-related charges, the Xinhua news agency reported on Thursday.

Zhou Yongkang was officially charged in April with disclosing state secrets, abuse of power, and accepting bribes following an investigation in 2014, which led to his expulsion from the Communist Party.

"The court rendered the above verdict based on the facts of Zhou Yongkang's crimes, their nature, circumstances and the degree of harm to society," the court said, according the AP news agency.

The 72-year-old man will be stripped of his political rights for the rest of his life, while his personal assets will be confiscated by the state.

Before retiring in 2012, Zhou was a member of the Politburo Standing Committee, considered the communist country's most powerful body.

He also headed the central Political and Legal Affairs Committee, which oversees law and order policy, from 2007 to 2012.

'I admit my guilt'

The court decision said Zhou plead guilty to the charges and would not be filing an appeal.

"I accept the prosecution's accusations, and the basic facts are clear; I admit my guilt and am penitent," Xinhua news agency quoted Zhou as saying.

Zhou is the most senior official to be sentenced following President Xi Jinping's pledge to crackdown on corruption. He had not been seen in public since 2013.

ls/msh (Reuters, AP, dpa)