It may not be unusual for six-year-olds to spend time on their computers, but when Humza Shahzad does it, he is not playing games.

Humza, from south London, has just passed three professional exams normally taken by adults and says he found them easy.

His father bought him a laptop when he was two and a half and taught him basic computing skills.

His case is not unique but has sparked a debate on how far to push children.

Humza's father, Asim, an IT consultant, said: "I didn't want him to waste time playing games on the computer so I focused his energy towards learning the computer."

Although both parents helped the Croydon youngster prepare for the first exam, Microsoft Word 2013, his mother, Seemab, says her son managed to teach himself for the subsequent papers.

Self-taught

He has since passed the tests for Microsoft PowerPoint 2013 and Excel 2013 - and is the youngest in the world to pass all three categories.

Mrs Shahzad says she is proud of her son's achievement.

"We had to put considerable effort to teach him in the first exam, but then he learned everything himself," she added.

Last year, five-year-old Ayan Qureshi also became a Microsoft Certified Professional after passing the tech giant's exam.

In the same year, Haris Khan, from the Republic of Ireland, became the youngest app developer in the world at the age of 10.

The list goes on, but raises questions over how far children should be pushed.

Child psychologist Laverne Antrobus says there should not be a problem as long as a balanced upbringing is provided.

"It's only one aspect of the child's life and other skills like sociability or emotional robustness should also be developed," she said.

The BBC spoke to a number of child psychologists who all said there was nothing wrong with tapping into a child's potential because children are good learners - but that there were caveats.

Tricky tests

Ruth Coppard, a child psychologist from Sheffield, says: "It's fine to give the child the opportunity and help develop their interest if they want it, but if children are pushed too hard, that can lead to depression later in life."

Another, Mamta Saha, said: "Pushing a child who has potential within boundaries can help them achieve great heights, but anything done in excess can have [an] adverse effect on the child - it might disengage them or they may go the other way."

Humza sat the exams at Best Training London South, in Streatham, south London. Those at the institute are amazed by the little boy's abilities, especially with his skills in MS Excel.

Kamil Krzysztof Procyszyn, head of ICT at the institute, said: "Microsoft's exams require really good understanding of their software and technologies." Candidates need to really put a lot of effort into preparation and practice in order to pass the exam."

He said the tests were usually taken by professionals who wanted to improve their job prospects.

Participants are provided with a virtual environment in which the capabilities of each individual are established through a series of problems and tasks.

School 'superstar'

Other Microsoft exams differ in that they are focused on memorising answers and filling out check boxes.

Humza has already been dubbed a "superstar" at his local primary school, the Ark Oval Academy, in Croydon.

Teachers at the school have praised the six-year-old and attributed most of his success to the support of his family.

They say he is a good role model for other children.

"Every child can make their dreams into reality and Humza has definitely shown you can achieve anything if you put your mind to it," said head teacher Sonia Rutherford.

Humza is already clear about his future. He wants to be like Bill Gates, the founder of Microsoft.

"I want to use my wealth to help poor people around the world to improve their lives," he said.