The schoolgirl, from the Lenadoon area of the city, allegedly fell pregnant after having sex with a 19-year-old man. 

If she carries to full-term, the young girl - whose family are said to be in shock - could become one of Britain's youngest mothers. 

Police confirmed that the 19-year-old had been arrested on Thursday after the pregnancy was reported to police.

He was arrested in relation to an alleged sexual offence and has been released on bail, pending further inquiries.

If it is found that he had sex with the girl, he faces being charged with rape, which can carry a life sentence upon conviction. 

Because those aged under 13 are not legally considered to be able to give consent to sex, those who engage in sexual activity with them face a charge of statutory rape.

A PSNI spokesman said: 'Police arrested a 19 year old man in the West Belfast area on Thursday 1st October in relation to a sexual offence. The man has been released on police bail pending further enquiries.'  

The teenager who is believed to be the UK's youngest mother gave birth last April after falling pregnant by her 13-year-old boyfriend while she was still in primary school.

The Year 7 pupil and the baby’s father, both from north London, were said to be ‘totally in love’ and had been going out for a year when she fell pregnant at the age of 11. 

She then gave birth at 12 years and three months, making her five months younger than Britain's previous youngest mother. 

With a combined age of 25, the pair were also believed to be the youngest British parents on record. 

At the time, the girl's father said he would be standing by his daughter and that he was glad she had fallen pregnant, rather than 'find she was on drugs'. He described the 13-year-old boy, whose identity has also been withheld, as a ‘great kid’.

Before last April, Britain’s previous youngest mother was Tressa Middleton, who gave birth aged 12 years and eight months in Edinburgh in 2006.

The country’s previous youngest parents were April Webster and Nathan Fishbourne, who were both 14 when their son Jamie was born in south Wales in 2010. 

The youngest father on record is Sean Stewart, of Bedford, who became a father aged 12 in 1998.  

According to figures released in February this year, rates of teenage conception in England and Wales are now at their lowest since records began in 1969.

The Office of National Statistics said the pregnancy rate for those aged between 15 and 17 was at 24.5 conceptions per thousand, a 13 per cent drop from the previous year. 

The under 16 conception rate was recorded as 4.8 per 1000 females - an estimate of 4,648 - which was a 14.3 per cent year-on-year reduction from 5,432 in 2012.

Since 1998, the under 18 conception rate has decreased by 47.9 per cent. The ONS believed the drop in the number of underage pregnancies could be due to improved sex education.

The report also said there had been a 'shift in aspirations of young women towards education' and the 'perception of stigma associated with being a teenage mother'.

The figures were released this year but relate to data collected in 2013.  

(dailystar.co.uk)