Four victims of imposter scams have sued the Japan unit of US IT giant Meta for damages, saying the operator of Facebook and Instagram has failed to verify the authenticity of social media ads.

The four plaintiffs, who are in their 40s to 60s, filed the lawsuit with the Kobe District Court on Thursday.

They say they have been swindled out of money after being lured to make investments via fake online ads featuring those pretending to be entrepreneur Maezawa Yusaku and other celebrity investors.

The plaintiffs say Meta is obliged to examine the content of its social media ads to prevent unexpected damage being inflicted on platform users. They claim the company was negligent.

The four are seeking a total of 23 million yen, or about 148,000 dollars, in compensation from Meta's Japan unit, Facebook Japan.

The lawsuit comes as cases of fraud by celebrity impersonators on social media ads are increasing.

The lawyers for the plaintiffs say the suit appears to be the first in Japan to attempt to hold a platform operator responsible over such scams.

Chief lawyer Kokufu Yasumichi told reporters that the group hopes to make clear it is impermissible to allow such harmful ads to remain online.

He said they will also underline the need for government regulations to prevent such fraud.

When contacted by NHK, Facebook Japan declined to comment on individual cases.