BEIJING (AFP) - The mother of the Briton whose murder led to the downfall of China's once high-flying Communist politician Bo Xilai has broken her silence, calling on authorities to show "decisiveness and compassion" to mitigate the consequences of his death.

Ms Ann Heywood told The Wall Street Journal newspaper that that the killing of her son Neil had left his two children, aged eight and 12, without financial security.

She expressed her "disappointment" with Chinese officials for not engaging with the family over the murder in Chongqing in November 2011.

China's foreign ministry did not immediately respond to a request for comment by AFP.

Bo, the former party chief of the southwestern city, has been indicted for bribery and abuse of power, and will be the highest-profile Communist official to be put on trial in China for decades.

Mr Heywood has been described as close to the Bo family, but the politician's wife Gu Kailai was convicted of his murder last year, when a court heard that they had fallen out after a business deal went sour.

French court filings obtained by AFP show that at one time Mr Heywood managed a villa in Cannes which was reportedly a fruit of Bo's alleged corruption.

In her statement to the Wall Street Journal, Ms Ann Heywood said that "circumstances now compel me to break my silence".

"I have been surprised and disappointed that, despite repeated discreet approaches to the Chinese authorities, there has been no substantive or practical response," the paper quoted her as saying.

She said her grandchildren were "particularly vulnerable to the hurt and horror of their father's murder and, since Neil was the family's sole breadwinner, to uncertainty and insecurity, there being no financial provision for their future".

"I hope and trust that the leaders of this great nation, which Neil loved and respected, will now show decisiveness and compassion, so as to mitigate the consequences of a terrible crime and to enable my family finally to achieve some kind of closure to our ongoing nightmare," she said.

Bo was a populist but divisive figure, whose "red revival" policies raised worries in some quarters over his leftist bent. His fall exposed deep divisions within the ruling Communist Party.

The scandal emerged last year ahead of a once-a-decade leadership transition, in which Bo had been considered a candidate for the Politburo Standing Committee - China's most powerful body.

His downfall was triggered after his police chief and right-hand man Wang Lijun fled to a US consulate in Chengdu city near Chongqing, allegedly to seek asylum. Bo was detained a month later.