A major new report from the Office for National Statistics has recognised that discrimination "could play a part" in the gender pay gap.
Women are paid on average 9.1 per cent less than men, data collected by the Office of National Statistics showed.
But, in some sectors, such as banking, the gap can be as wide as 32 per cent, according to last year’s figures.
Fresh analysis by the Office of National Statistics claims that more than two-thirds - 61 per cent – of the gap cannot be explained by factors such as age, seniority and tenure.
A report, released on Wednesday, said that although the unexplained element of the pay gap “should not be interpreted as a measure of discriminatory behaviour, (.,,) it is possible that this plays a part.”
Researchers added that the unexplained pay gap may also be down to unrecorded factors including the number of children an employee has, the length of career breaks taken and a person’s level of qualifications.
The report said: “Factors such as the number of children, the age of children, whether parents have any caring responsibilities, the number of years spent in school and the highest level of qualification achieved are likely to improve the estimation of men’s and women’s pay structures and consequently decrease the unexplained element of the pay gap.”
Figures also showed that millennials are less likely than older women to be affected by the gap.
There was a 16.2 per cent gap between female and male full-time workers aged 50 – 59 were affected by the pay gap as opposed to just 2.2 per cent for 20 to 22-year-olds and 2 per cent for 30 to 39-year-olds.
Women who have worked full-time in the same company for more than 20 years are more than twice as likely to be paid less than men (11.9 per cent) compared to those who have been working for the same company for less than a year (5.3 per cent).
The report comes weeks after the BBC’s China Editor Carrie Gracie quit in a row over unequal pay.
In an open letter to viewers she accused the corporation of a "secretive and illegal pay culture" after it was revealed two-thirds of its stars earning more than £150,000 were male.
The letter says: "My name is Carrie Gracie and I have been a BBC journalist for three decades. With great regret, I have left my post as China Editor to speak out publicly on a crisis of trust at the BBC.
"I am not asking for more money. I believe I am very well paid already - especially as someone working for a publicly funded organisation. I simply want the BBC to abide by the law and value men and women equally."
A BBC spokesman said: "Fairness in pay is vital. A significant number of organisations have now published their gender pay figures showing that we are performing considerably better than many and are well below the national average.
"Alongside that, we have already conducted an independent judge-led audit of pay for rank and file staff which showed 'no systemic discrimination against women'.
"A separate report for on-air staff will be published in the not too distant future."