The Information Centre for health and social care said in 2004-05 the average net income for GPs in England was£103,564.
This compares with£91,588 in Wales,£91,151 in Northern Ireland and£82,696 in Scotland.
But English GPs received only a 22.1 per cent increase in pay, compared with 23.8 per cent in Wales, 24.9 per cent in Scotland and 34.9 per cent in Northern Ireland.
A statement from the British Medical Association said the numbers could be 'misleading' as the figure included private work, such as insurance medicals, as well as NHS work.
It said the average net income figure had included the 'minority' of dispensing GPs. Non-dispensing GPs' average income was£96,593, it said.
A BMA spokeswoman said lower list sizes in Scotland and differences in the way disease prevalence payments under the quality and outcomes framework are paid accounted for some of the disparity.
BMA GPs committee acting chair Dr Laurence Buckman said: 'As agreed with the Department of Health and signed off by ministers, the contract delivered a planned uplift in income. The pay increase was essential as, while workload had increased, GP income had fallen behind and job vacancies could not be filled.'