Fifty-three per cent of students with Indian backgrounds gained five or more grades at A* to C in Leicester last year, compared to the 47 per cent national average.
Only 31 per cent of white students gained the same amount of passes and the figure would have been even lower if data from two closed schools had been taken into account.
Children living on predominantly white council estates were most likely to underperform, according to the local authority. The proportion of black Caribbean and Bangladeshi students gaining five A* to C grades was also low.
The statistics were revealed in an analysis of attainment carried out in the wake of a report from the Office for Standards in Education last year that criticised the LEA's ethnic monitoring.
The analysis found that Leicester pupils from Indian backgrounds were outperforming at both local and national levels, while white pupils were badly under-achieving, at well below both national and local levels.
Assistant education director John Crooks said: "White pupils perform less well on every measure, except key stage 2 science, than the city average and have a partcularly poor performance at GCSE. The 13 per cent of white pupils not gaining any GCSE qualifications is also worrying."
"The current level of outcome at GCSE for white, black and Bangladeshi students is of particular concern. Action needs to be taken for each of these communities."
He said heads leading schools serving white, working-class estates had to be challenged to raise expectations and develop more effective teaching and learning strategies to raise standards.
The LEA is now planning to investigate the interaction between language acquisition, parental support and school expectations affecting high performing pupils of Indian origin in a bid to apply the lessons learnt to under perfoming groups.
Chris Myant, spokesman for the Commission for Racial Equality, said it was vital that LEAs monitor ethnic achievement.
"If we do not know what the problems are, we will not be able deal with them or understand the nature of the success stories.
"This needs to be nationally driven and co-ordinated so we produce proper, comparable results but it is something that all LEAs need to take responsiblity for.
"We need to zero-in on the reasons why Indian origin pupils are successful and see how they can be spread to other white and non-white groups."