NICOSIA (AFP) - Cyprus said on Wednesday (Oct 23) it will investigate reports that family members and allies of Cambodia's long-time Prime Minister Hun Sen had obtained Cypriot EU passports under a citizenship-for-investment scheme.

"There will be an investigation into cases of naturalisation that have appeared in the media... If anything untoward is found, decisions will be taken, including revocation of citizenship if required," government spokesman Prodromos Prodromou told reporters.

He said the interior ministry would carry out the probe into cases predating the introduction of more stringent regulations on the citizenship scheme, without referring specifically to the Cambodian case.

Last week, opposition deputy Irene Charalambides, a special representative on fighting corruption for the Organisation for Security and Co-operation in Europe (OSCE), said Cypriot authorities must respond to the findings of a Reuters investigation.

The investigation said members of Cambodia's elite had overseas assets worth tens of millions of dollars and used their wealth to buy foreign citizenship - a practice the premier has decried as unpatriotic.

It said they acquired Cyprus passports in 2016 and 2017.

Cyprus, an EU member since 2004, has said it does not name applicants who receive a "golden passport" through the investment scheme.

In February, it made changes to make the programme more "trustworthy" after the European Commission said it could help organised crime gangs infiltrate the bloc.

Under the new criteria, a Cyprus passport is granted in exchange for an investment of EUR2.5 million (S$3.8 million), raising the bar from EUR2 million.

Nicosia says due diligence procedures are more stringent and effective, such as the scrutiny of each applicant by an international agency.

The scheme was launched in the aftermath of the island's 2013 economic crisis.