The wife of disgraced Chinese politician Bo Xilai and a family aide have been charged with the murder of a British businessman, state news agency Xinhua has reported.

Xinhua said on Thursday that the prosecutor's indictment said Bo's wife, Gu Kailai, had a falling out with Briton Neil Heywood over money and worried that it would threaten her and their son's safety.

Gu and the aide, Zhang Xiaojun, are alleged to have poisoned Heywood together, the report said.

"The facts of the two defendants' crime are clear, and the evidence is irrefutable and substantial. Therefore, the two defendants should be charged with intentional homicide," Xinhua said.

It did not give a date for the trial, but a family lawyer told the Reuters news agency it was likely to take place on August 7-8.

The announcement comes months before the ruling Communist Party unveils a new top leadership.

Heywood was found dead in a hotel in Chongqing in November last.

Local officials initially said he died of excessive drinking, but the government announced in April it was investigating Bo's wife in connection with the case.

They were charged in the eastern city of Hefei, Xinhua said.

It did not say when exactly the indictment was issued or when the crime occurred and why the case is being prosecuted in Hefei and not in Chongqing, the metropolis Bo ran as Communist party secretary and where the couple lived.

Prosecutors have interrogated Bo and Zhang and have "heard the opinions" of their defence lawyers, Xinhua said.

Bo, the former leader of the south-western Chinese province of Chongqing, was sacked in March and is now under investigation for a string of accusations ranging from an abuse of power to flouting rules against the Communist party.

Bo, 62, was widely seen as pushing for a spot in that new leadership until felled by the scandal brought to light by his former police chief, Wang Lijun.

The removal of Bo has triggered rifts and uncertainty, disrupting the Communist Party's usually secretive and carefully
choreographed process of settling on a new central leadership in the run up to its 18th congress.