Another case concerned a 13-year-old girl who said she was forced to marry an 18-year-old Iranian over Skype.
Prem said Skype marriages were attractive to some families because the marriage was instant and they were less likely to get caught.
Karma Nirvana, another British charity which campaigns against forced marriage, said it had received calls to its helpline from girls who had been married off over the phone.
The girls often don't realise the phone call is a marriage ceremony until their family tells them afterwards.
"Some victims have contacted us and said: 'I've been married over the phone because my family think that I'm shaming them.'," said Karma Nirvana founder Jasvinder Sanghera.
"The quickest way to marry someone off is not going to be taking them out to Pakistan, India, or wherever, the quickest way to get them into marriage is going to be over the phone." Karma Nirvana helpline manager Priya Manota estimated thousands of British girls under the age of 18 are being forced into marriage every year.
Britain's Forced Marriage Unit confirmed it had come across cases of forced marriage being conducted by Skype."Forced marriage is an abhorrent practice which is totally unacceptable and will not be tolerated in the U.K., regardless of how it takes place," the Home Office said.LONDON - Girls in Britain as young as 11 are being forced into marriage via the internet while others are being secretly wed over the phone, two charities said on Monday.Imams in Britain and abroad have been conducting ceremonies using Skype to marry British girls remotely to men abroad, said the charity Freedom, which campaigns against forced marriage.The new husband is often promised that he will get a visa to come to Britain.