A Chinese court has ruled that artefacts recovered from a tomb cannot returned to their original owner's descendants because they belong to the state, media reported on Tuesday.

Two brothers from the central province of Henan took a local government relics bureau to court after it decided that 32 treasures -- including emerald bracelets and rings -- which were stolen from their grandfather's tomb could not be returned to them.

But the Intermediate People's Court of Pingdingshan in Henan ruled that the goods belonged to the country, the state-run Dahe Daily reported.

The artefacts had been stolen from the underground tomb and were recovered by local police, the report said.

The newspaper reported that by law all artefacts found underground belong to the government.

Tomb raiding occurs with some regularity in China, whose ancient civilisation has left a wealth of relics underground. Police investigated 451 tomb-raiding cases in 2010, state media said.

Two grave robbers trapped underground in a Tang dynasty tomb for more than 24 hours were rescued by police who promptly arrested them, state media reported last year.