The wife of controversial Chinese politician Bo Xilai has been formally charged with murder, the state-run Xinhua news agency said Thursday.
She is Gu Kailai, suspected of killing British businessman Neil Heywood.
Her husband had been one of the country's most prominent politicians until he was sacked as the chief of Chongqing in what has been seen as a political power struggle.
He remains under house arrest and is under investigation for flouting Communist Party discipline.
Chinese authorities announced that the two were arrested earlier this year on suspicion of intentional homicide and had been jailed.
Authorities say Gu and her son came into conflict with Heywood over "economic interests."
They said she regarded Heywood as a threat to her son's safety. Gu and Zhang poisoned Heywood, authorities said.
The two are awaiting trial in Hefei city, the capital of eastern China's Anhui province.
Heywood was found dead in a hotel in the southwestern Chinese metropolis of Chongqing in November. Initially, the cause of death was reportedly found to be excessive alcohol consumption, and his body was cremated without an autopsy.
But Britain asked China earlier this year to investigate the matter further after being informed of growing concern about Heywood's case.
Speculation has been rife about the nature of Heywood's work in China and his ties to Bo's family.
Heywood had lived in China for more than a decade and was married to a Chinese woman. Among the companies Heywood advised was Hakluyt and Co., a consulting firm founded by former officers of the British spy agency MI6.
That link fueled rumors that Heywood might have had connections to British intelligence services.
But British Foreign Secretary William Hague denied that possibility.
"Mr Heywood was not an employee of the British Government in any capacity," he said in a letter.
Hague noted that government policy is usually "neither to confirm nor deny speculation of this sort."
But he said he was making an exception, "given the intense interest in this case."