TOKYO (AFP) - An 86-year-old Japanese woman who allegedly carried on cashing her parents' pensions for half a century after they had died has been arrested, the police said on Friday.

Ms Mitsue Suzuki is believed to have collected more than 50 million yen (S$556,500) over the last five decades for her parents, who would now be among the world's oldest people if they hadn't died in the 1960s.

The case is the latest in a series in Japan where welfare payments have continued long after someone's death. In some instances, claimants have lived with the corpse of their late relative in order to keep cashing the cheques.

Ms Suzuki's alleged crime came to light when a pensions agency official contacted the local authority in Gifu, central Japan, to ask after the health of a woman who was 110 and her 112-year-old husband.

The world's oldest man is 112-year-old Mr Sakari Momoi.

But Gifu officials said both had long since died - and they had been given death certificates in the 1960s.

An officer at Gifu Prefectural Police told AFP that Ms Suzuki had been arrested on Thursday for allegedly receiving 2.6 million yen between April 2013 and December 2014.

Detectives are examining whether they can expand this time period to cover more alleged claims without falling foul of the statute of limitations.

Ms Suzuki has denied any wrongdoing, the officer said.

With its ageing population, Japan is no stranger to pension fraud. In 2010, the police arrested a family in Tokyo for allegedly collecting 18 million yen in pension payments in the 30 years after the death of Mr Sogen Kato.

Mr Kato's family did not report his death, and kept his mummified corpse at their home, saying he wanted to become a living Buddha.

Following the incident, the Health Ministry began a nationwide investigation into missing elderly people who were still receiving pensions.

Payments for around 1,700 missing pensioners has been suspended since the probe began.