BEIJING (AFP) - Autopsy results into the deaths of two young sisters found dead in a washing machine show that no foul play was involved, state media reported on Wednesday.

Police in eastern China's Jiangxi province had launched a probe after online suspicions were raised over the deaths of the girls last month in their home, the official Xinhua news agency reported.

But a statement issued on Wednesday by police in the Jiangxi city of Nanchang said they died of chest injuries and heart and lung failure due to the high-speed spinning of the machine, Xinhua said.

No motive for the children to have been murdered by their parents or anyone outside their family was uncovered, the police statement said, according to Xinhua.

The case had raised suspicions amid questions over how the machine could have operated with the two girls, which were said in a police report last month to be aged two and three, both inside it.

Police, however, said that experiments conducted with the washing machine model involved in the case found that it could commence spin drying if two girls of similar size as the sisters crawled in and closed the lid, Xinhua said.

An account in a Jiangxi-based online news portal and cited by China's Global Times newspaper last month quoted a witness said to have helped take the girls to a hospital after they were found as describing their bodies as swollen and bruised and that there had been a lot of blood in the washing machine.