Women are earning more than men in some public sector organisations - but only in the lower-paid grades, according to new research by the BBC.
Female clerical and admin staff are taking home bigger salaries than their male colleagues in 14 out of 17 public sector bodies which responded to a Freedom of Information (FOI) request about pay.
Figures showed that, on average, women in these grades were earning up to £350 a year more than men.
But higher up the career ladder it's a more familiar story, with male earnings outstripping females' and men outnumbering women in the senior management roles.
Gender pay gap
In fact, our figures suggest men are being paid more than women in eight out of the 11 grades for which there were sufficient figures to obtain an overall average; with the pay differential starting at a few hundred pounds but rising to several thousand pounds a year, higher up the pay scale.
It all goes to show the gender pay gap is still alive and well in 2009.
Although it has narrowed from about 45% in 1970 - the Office for National Statistics (ONS) suggests that men working full-time are paid an average hourly rate that is 17.3% higher than that earned by women.
When part-time workers are taken into account, the figure rises to 23%, because there are disproportionately more women working part-time.
In three of the organisations which replied to our survey, the overall gender pay gap exceeded 20%: English Heritage, the Bank of England and the Foreign Office.
Lower pay grades
So why do women appear to make a good start on the career ladder, but fail to progress?
Our research showed the Scottish Government, Department of Health, Culture department, Environment Agency, Audit Commission, Business and Enterprise department (BERR) and Equality and Human Rights Commission (EHRC) at the time of the survey were all paying women more than men in the two lowest grades.
The Department of Health, Bank of England, Communities and Local Government department (CLG), Foreign and Commonwealth Office, Department for International Development (DIFD), BBC and Treasury were all paying women more than men in two out of the three lowest pay bands.
TUC Senior Equality Policy Officer Sally Brett says: "I have known organisations try and present the positive pay gaps in lower grades as a good news story but this often reflects the lack of progression of many women.
"They are more likely to get stuck in low grades for a long period of time, especially if they work part-time so get long service and greater experience in that grade whereas men may only be in that grade for a short period of time before they move upwards and into higher grades."
Figures provided by the ONS suggests the gender gap does increase with age and begins to stretch once women take time off to have children.
Dr Susan Harkness, Senior Lecturer in Social Policy at Bath, agrees: "Maybe it's the older women and women returners (from maternity leave) who are doing relatively well ... and they just stick in these relatively low grade jobs and progress to the top of the pay scale, whereas men use them as more transitory and move up the pay grades.
"Also a lot of women with childcare responsibilities are quite constrained so they don't have the same opportunities. If you know you've got to go and pick up your children, these jobs accommodate that more easily."
Only two of the organisations which gave precise details about their most senior layer of management employed a woman at at the top of their organisations - DFID and Department for Environment, Food and Rural Affairs (DEFRA) - suggesting the glass ceiling is still firmly in place.
In the organisations surveyed where the gender pay gap appears biggest, the figures show senior management dominated by male staff.
An annual survey carried out by the EHRC, the Sex and Power index, reckons that women represent less than a quarter of the staff employed at senior level in public and voluntary sector organisations.
In two of the the organisations which responded to the BBC's FOI request which had the biggest gender pay gaps - English Heritage and the Bank of England - most of the senior posts were held by men.
According to the figures obtained by the BBC, English Heritage has an overall gender pay gap of 20.5%. It is also one of only two organisations surveyed where men earned more than women at every pay level.
Terry Clark is Head of Reward, Recognition and Retention at English Heritage: "In our case, a lot of the difference is determined by history. We have had long incremental scales, so you would join a grade low down and move up.
"Now the difficulty is that if you have longer service, you get higher up the scale. Generally speaking, women have shorter periods of service than men, so you have an in-built mechanism to produce a higher mean salary for men."
The figures bear out ONS statistics which show that, nearly 30 years after the Equal Pay Act came into force, the gender pay gap has narrowed but is still a long way from closed.
Academics Professor Alan Manning and Dr Joanna Swaffield studied early career growth in the gender gap.
According to their research, men and women tended to enter the labour market at the same level but within 10 years a sizeable gap had emerged which continued to increase until reaching a maximum about 20 years into a career.
Dr Swaffield said: "I think there are probably a lot of factors going on - lower pay grades are more likely to offer part-time positions.
"When women start having children they withdraw to be at home more or feel they are unable to make the commitments in the work environment.
"This has a funnelling affect on people as you go up the grade, women are making the choice not to be in the labour market."
Professor Manning agreed: "Most women take some time out of paid employment to have children and look after children ... and if you have less experience, then it's not that surprising you earn a little bit less."
But he says his research with Jo Swaffield showed that women who worked full-time for 10 years after entering the labour market were still earning about 12% less than their male counterparts.
He said this could be "because employers think women are very likely to take time out so they are less likely to promote them"; or perhaps that women's "psychological profile" means they are less likely to push for promotion.
"Women tend to be less confident, and have lower self-esteem than men," he adds.
But, he says, nobody who has studied the issue of the gender pay gap so far has managed to explain it fully - it remains a mystery.