Federal police have raided the offices of a Reserve Bank subsidiary in Melbourne in the latest part of a scandal involving plastic banknotes in other countries.

The raids happened yesterday, with police executing a search warrant on commercial premises and on the homes of managers connected to the company.

It is a serious development in a scandal that has been unfolding around Securency International, a company half owned by the Reserve Bank.

It involves multimillion dollar payments in deals for printing plastic banknotes in other countries.

The AFP also raided the homes of Securency's managing director, Myles Curtis, in Mont Albert north, and that of another senior manager in Roxburgh Park.

No one has been arrested or charged and the AFP's investigation is continuing.

It is understood police seized computers and files.

Plastic banknotes

Securency International manufactures the polymer material which is used in Australian banknotes.

The patented polymer formula is now used in 27 other countries, including Vietnam, which switched to polymer notes in 2002.

Hanoi businessman Anh Ngoc Luong played a major role in the deal and last month it was revealed that Securency paid Mr Luong and his company more than $12 million.

It is claimed Mr Luong is a Vietnamese government official.

Under Australia's federal bribery laws, it is illegal for Australian companies to pay foreign officials or government-controlled entities to gain a business advantage.

If it can be proven that Securency executives knew or should have known that Mr Luong worked on behalf of the Vietnamese government, they may face criminal charges, which carry a 10-year jail sentence.

The allegations also raise questions about the conduct of the Reserve Bank, because some of its officials sit on the Securency board and oversee its activities.

The Department of Foreign Affairs and Trade and other Australian agencies also work with Securency around the world.