The South African Citizenship Amendment Act, which comes into effect in January, will impose stiff penalties on both the foreigner and the South African helping the foreigner to obtain citizenship by means of an illegal marriage of convenience.

The Department of Home Affairs said that during the 2011-2012 financial year there were 1209 fraudulent marriages involving foreigners and 2852 the previous year.

Yesterday, the department's deputy director-general for civic services, Vusi Mkhize, told parliament that the current law was too lenient.

"Once the new act comes into effect there will be a penalty of 15 years [for] anyone who aids and abets because for too long we've been ignoring this issue by just deporting [foreigners entering into illegal marriages] or nullifying the marriage," said Mkhize.

He said often foreigners came to South Africa as visitors then claimed asylum. Shortly afterwards, they would buy or rent a spouse. The going rate was about R10000 as a once-off payment, or "rent" of R2000, he said.

Once the foreigners acquired citizenship, they would divorce, making it possible for their real spouse and children to enter the country.

According to the department's 2011-2012 annual report, investigations in Durban uncovered hundreds of sham marriages, with foreigners often marrying teenage girls from poor backgrounds.

One investigation led to the arrest of five Home Affairs officials, priests and marriage officers, implicated in fake marriages scams.

Mkhize said the new biometric smart card IDs, with enhanced security features, would make it harder for IDs to be counterfeited.

Beefed-up security at regional and metropolitan Home Affairs offices would help to curb bribery.

He said the new act would prevent immigrants from ensuring that they bore children in South Africa so that the children would gain citizenship and the family be eligible for social grants.

According to the act, only a child born to a South African parent and recorded as such in the birth register will gain automatic permanent citizenship.

Earlier this year, Home Affairs director-general Mkuseli Apleni told parliament that, though the exact number of illegal immigrants was not known, South Africa attracted the highest number of asylum seekers in the world.