Updated

A French citizen detained last month in Cambodia for alleged links to an explosive Chinese political scandal was freed and flew to China voluntarily to help its investigation, Cambodian officials said Wednesday.

Police released Patrick Devillers in Phnom Penh on Tuesday after China formally requested it. Cambodian Interior Ministry spokesman Khieu Sopheak said Beijing had assured the Frenchman he would be allowed to leave China within 60 days.

Cambodian authorities detained Devillers on June 13 for possible links to the death in China last November of British businessman Neil Heywood, but he has not been charged with any crime. Heywood had close ties to Bo Xilai, a Chinese political high-flier who was ousted as Communist Party chief of Chongqing city earlier this year.

China had asked Cambodia to arrest Devillers so he could be interrogated and sought his extradition. But Cambodian officials said they would not hand him over unless they obtained proof of wrongdoing.

Cambodian government spokesman Khieu Kanharith said Beijing gave Devillers assurances he would be allowed to leave China within two months if he promised to help Chinese investigators. After his release, he voluntarily boarded a plane to China on Tuesday night, Kanharith said.

Sopheak said Devillers would not have gone if he had been "facing imprisonment" in China.

Beijing did not report his arrival or comment on its investigation.

Bo, the politician, fell from power after his former police chief and longtime aide fled to a U.S. consulate and divulged suspicions that Bo's wife, Gu Kailai, was involved in Heywood's death.

Bo was subsequently removed as Chongqing party secretary in March and then suspended as a Politburo member amid speculation he tried to quash an investigation of his wife and a household employee over the Briton's death. And the former police chief, Wang Lijun, resigned from the national legislature last month — a sign that he might be a step closer to formal arrest and trial.

Though authorities in China initially said Heywood died from either excess drinking or a heart attack, they have since named Gu as a suspect.

News reports have said that Devillers, an architect, was closely linked to Bo, Gu and Heywood, and had helped Bo rebuild the northeastern Chinese city of Dalian when Bo was the city's mayor in the 1990s.

China has considerable influence in Cambodia, having provided millions of dollars in aid over the past decade.