Politician's wife 'killed Briton to keep her financial affairs secret'

The British businessman Neil Heywood, whose death has sparked political upheaval in China, was poisoned after he threatened to expose a plan by a leading politician's wife to move money abroad, it was claimed yesterday.

The allegations, which follow an investigation by Reuters, give for the first time a specific motive for Mr Heywood's murder last November, a death that ended Chinese leader Bo Xilai's hopes of emerging as a top central leader and threw the Communist Party's looming leadership succession off balance .

The two sources for the investigation have close ties to Chinese police and said they were given details of the circumstances into the 41-year-old Mr Heywood's death. Mr Bo's wife, Gu Kailai, asked Mr Heywood late last year to move a large sum of money abroad, and she became outraged when he demanded a larger cut than she had expected due to the size of the transaction, the sources said.

She accused him of being greedy and hatched a plan to kill him after he said he could expose her dealings, one source said, summarising the police case. Both sources have spoken to investigators in Chongqing, the south-western Chinese city where Mr Heywood was killed and where Mr Bo had cast himself as a crime-fighting Communist Party leader.

Ms Gu is in custody on suspicion of committing or arranging the murder, though no details of the motive or the crime have been publicly released, other than a general comment from Chinese state media that he was killed after a financial dispute. They said Mr Heywood – who was formerly a close friend of Ms Gu and and had been helping her with her overseas financial dealings – was killed after he threatened to expose what she was doing.

"Heywood told her that if she thought he was being too greedy, then he didn't need to become involved and wouldn't take a penny of the money, but he also said he could expose it," one source said. The sources said police suspect Mr Heywood was poisoned by a drink. They did not know precisely where he died in Chongqing. David Cameron will raise Mr Heywood's death at a meeting in Downing Street today with a senior official from the Chinese Communist Party.

The talks with politburo member Li Changchun were set up to discuss trade, educational and cultural links between the two countries. But Downing Street yesterday confirmed Mr Cameron planned to ask him about the businessman's mysterious death. A spokeswoman said: "I think he will echo what the Foreign Secretary has said, that we welcome the investigation that is ongoing and we look forward to seeing the outcome of that."

Mr Li is the first senior Chinese official to visit the UK since it was reported that Gu Kailai had been arrested on suspicion of murder. The Foreign Office has been under pressure over its response.