Some marriages are made in heaven, but some are made in a fraudulent scheme to obtain legal grounds to live in the European Union.

Axar.az reports citing foreign media that, four people have been detained in Bulgaria on suspicion of arranging sham marriages for citizens of India and Pakistan seeking EU residence permits, the Sofia Globe news site reports, citing Bulgaria's Interior Ministry.

The report alleges that two Bulgarian women, a Bulgarian man and an Indian man were responsible for the scheme; they have been placed in custody for three days while the investigation is still underway.

The two-year probe into the scam revealed that the group recruited women in the country's capital, Sofia, who were willing to tie the knot with men from India and Pakistan in return for money.

It was revealed that the non-EU newlyweds would register at addresses in the countries where the marriage was conducted − in Bulgaria as well as in Western Europe and Cyprus.

Afterwards, they would apply for status as a long-term EU resident through their marriage to a European Union citizen.

Bulgaria is among a group of European countries that have recently clamped down on marriages conducted with the sole purpose of obtaining residence benefits.

In Ireland, the number of people (most of them men from Asian countries) being investigated for suspected participation in this scheme has reportedly doubled in the past years.

In January, seven people were arrested in Spain for arranging fake marriages and providing false marriage certificates. The group was found to have registered around 30 foreign citizens.

It also emerged last summer that Finland had seen an increase in the number of Iraqi asylum-seekers marrying local citizens in order to get residence permits.

In June 2018, an organised crime group that unlawfully assisted Asian migrants in obtaining EU residence permits using sham marriages was busted by German and Danish authorities. The group was accused of having smuggled nearly 1,200 migrants into the union.