Citizenship of the European Union that would allow non-Europeans to live and work in Britain can be bought for £150,000, it has been reported.
A scheme in Bulgaria means applicants can obtain a passport for the country without having to live or work there, an investigation by the Daily Telegraph found.
People can deposit sufficient funds in a Bulgarian bank and brokers will help them set up a "virtual" address which is valid with immigration authorities.
The arrangement, which is legal, will then allow them to apply for European citizenship, meaning they can eventually live, work and send their children to school in the EU.
Bulgarian agents brokering the deal told the Telegraph that even people with a criminal record who have been turned down for a British passport can qualify for Bulgarian citizenship.
The revelation comes after restrictions on Bulgarian and Romanian nationals living and working in other EU countries were lifted earlier this year.
Posing as representatives for an Indian businessman, Telegraph reporters were told by a Bulgarian passport broker of three routes to obtaining citizenship of Bulgaria, for which the firm charged a fee of more than £50,000.
One involved an individual paying £425,000 into a Bulgarian bank and receiving "permanent residency" after six months, allowing them to apply for European citizenship after five years, at which point they would receive their money back.
A second, the Telegraph said, involved the applicant borrowing £425,000 from a Bulgarian bank and paying the institution around £150,000 interest up front. They can again then apply for citizenship after five years.
A third method enabled applicants to pay around £235,000 for a fast-track to citizenship after two years.
The passport broker told the newspaper that potential clients would only have to visit Bulgaria for a day or so to qualify for citizenship, as the firm could supply them with a "virtual" address that is valid when checked by immigration authorities.
A lawyer at a second firm told the Telegraph that clients might be able to get an EU passport even if they had a criminal record, as older crimes are "rehabilitated" and do not show on certificates.
The Telegraph said neither firm was acting illegally or improperly as they were simply explaining how the Bulgarian passport scheme operates.