Britain's senior politicians urged China on Tuesday to ensure that an investigation into the suspicious murder of a British businessman is free from political meddling and quickly uncovers the facts.

Prime Minister David Cameron and Foreign Secretary William Hague both held talks with China's propaganda chief, Li Changchun, during his visit to Britain and demanded assurances over inquiries into the death of Briton Neil Heywood.

Heywood, whose body was found Nov. 15 at a mountaintop hotel on the outskirts of the southwestern city of Chongqing, had close ties to Bo Xilai, a political high-flier whose career has been derailed by the death.

Chinese authorities have named Bo's wife Gu Kailai as a suspect in Heywood's murder amid a new inquiry into his killing.

Hague told legislators in a written statement that Britain had made a total of four requests to China to reopen the case before authorities there announced last week that a new investigation had begun.

Authorities in China initially had said Heywood died from either excess drinking or a heart attack. His body was cremated without an autopsy.

"I welcome the fact that the Chinese authorities have now committed themselves to undertake the investigation into Mr. Heywood's death that we sought," Hague said.

Bo was removed as Chongqing's Party Secretary on March 15 and has been suspended as a Politburo member amid questions over whether he tried to abuse his power to quash an investigation into his wife and a household employee over the Briton's death.

"We now wish to see the conclusion of a full investigation that observes due process, is free from political interference, exposes the truth behind this tragic case, and ensures that justice is done," Hague said in a statement.

Cameron's office said the leader had told Changchun that Britain was eager to see China "address concerns about the suspicious circumstances."

Changchun thanked Cameron for an offer of help in the case and vowed that Chinese officials would keep in close contact with their U.K. counterparts, the British leader's office said.

Bo was fired after Chongqing's former chief of police, Wang Lijun, visited the U.S. consulate in Chongqing on Feb. 6 to raise concerns about the Heywood case. Hague confirmed that Wang had detailed his suspicions about the death of Heywood to the Americans, who then contacted British diplomats.

From mid-January British diplomats had also become aware of "rumors within the British expatriate community in China that there may have been suspicious circumstances," casting doubt on the original findings over the death.

"Prompted by these increasing concerns ... I immediately instructed them to make urgent representations to the Chinese authorities and to seek an investigation into Mr. Heywood's death," Hague told legislators in a written statement.

Chinese authorities have confirmed that Heywood previously had a close business relationship with Gu and the couple's son, Bo Guagua, who attended schools in Britain, but that the ties had recently soured.

Hague said that Jeremy Browne, a junior Foreign Office minister, was visiting China at the time of Heywood's death, and met with Bo in Chongqing on Nov. 16 — a day after Heywood's body was found.

However, Browne was unaware of Heywood's killing at the time, Hague said.

"Ministers are not routinely told about the death of British nationals ... however we need to make sure that they are told in relevant cases and we will review our procedures," Hague acknowledged in his statement.