Black and Asian families are twice as likely as white families to hire a private tutor for their children, research suggests.
The survey, conducted for educational charity the Sutton Trust, reveals that 42 per cent of Asian state-school pupils and 38 per cent of black pupils have received private or home tuition. This compares with 20 per cent of white pupils who have had extra help.
Overall, the use of home tutors has risen by almost a third in the last six years as more and more parents seek an advantage for their offspring, according to the study.
Rosalyn George, professor of education and equality at Goldsmiths, University of London, said the results show many ethnic-minority parents feel schools are not meeting their needs and are more willing to make sacrifices to give their children a leg up.
"I think there is a disenfranchisement with the system," Professor George told The TES. "Spending money on private tuition indicates a greater priority given by ethnic-minority parents on maximising their children's potential. As exam results go up year on year, there's a recognition of the importance of getting the necessary credentials to go forward to higher status degrees and well-paid professions."
Some local authorities pay for home tutors for disadvantaged children, but it is parents willing to spend between #163;20 and #163;60 an hour for extra lessons that are thought to be mainly driving the home-tutoring boom.
"Class is such an important issue in this," Professor George said. "We know that higher-income families invest more in education in order to secure greater advantage for their offspring.
"If you look at the kids who are not doing well in the system it is white working-class boys and those from Afro-Caribbean backgrounds. It's not helpful to ignore social groups."
The research was carried out by polling specialist Ipsos Mori, which surveyed 2,739 state-school pupils aged 11-16 across England and Wales.
It showed a total of 23 per cent had received private or home tuition, a marked increase from 18 per cent in a similar survey in 2005.
The home-tutoring boom is strongest in Greater London, where nearly four in 10 children (38 per cent) have been privately tutored at some time, compared with just 9 per cent in Wales and 10 per cent in north-east England.
Unsurprisingly, affluent families are most likely to benefit from a private tutor's time, with 25 per cent of children having extra lessons compared with 15 per cent of children from lower income families.
Pupils in Year 7 and Year 11 were most likely to have been tutored in the last 18 months. There was little difference between boys and girls.
Sutton Trust chairman Sir Peter Lampl warned that the growing reliance on tutors could widen social inequalities as poorer children miss out. He said: "Private tuition appears to be booming despite the recession.
"While it is natural that parents should want to do the best for their children, it does give well-off families an advantage, particularly when money to help children from poorer homes is being cut."
The trust has funded a pilot scheme to give 100 pupils from poor homes in London one-to-one maths tuition to see if it boosts their GCSE scores compared to others who had no extra help.
- 23 per cent of state-school pupils aged 11-16 said they have had private tuition at some time - up from 18 per cent in 2005.
- Across all ages an average of 13 per cent were tutored in 2010 or 2011 - but this rises to 18 per cent of Year 11 students.
- There were strong regional differences, with 38 per cent of pupils having received tuition in Greater London and 27 per cent in north-west England, but 10 per cent or less in Wales, the North East, and Yorkshire and Humberside.
- Asian children were the most likely to have had tutors at 42 per cent, followed by black children at 38 per cent, those classed as from "other" racial backgrounds at 29 per cent, "mixed" at 22 per cent, and white children the least at 20 per cent.
- 25 per cent of children from affluent families had tutors, but only 15 per cent of those from less affluent families.