Male fundraisers earn on average 20 per cent more than their female counterparts, a survey by the recruitment service Robertson Bell has found.
The survey of more than 1,000 fundraisers, conducted over the 12 months to January, also found that almost half of them were planning to move on to new jobs in the next six months.
Women made up 70 per cent of respondents to the survey and, it found, the number of women in senior positions was almost on a par with the number of men.
But the report says: "Heavily in the news, and in line with national statistics, the gender pay gap within the charity fundraising sector does appear to exist."
The survey found the average salary for a man working in fundraising was £54,811 a year, while the figure was £45,664 for women.
And even at director level, men earned on average 11 per cent more than women.
Respondents specialising in major-donor fundraising were the highest earners, averaging £48,392.
The report also says that charities could face a challenge in retaining fundraising staff: 45 per cent said they were looking to change positions in the next six months.
The report says there was further evidence of "a buoyant candidate market".
It adds: "Over 70 per cent of respondents are open to new opportunities and willing to move for the right reasons."
The reasons given by those who said they would be willing to move on included more money, cited by 55 per cent of respondents, promotion (43 per cent), better benefits (27 per cent), moving to a charity with a particular cause (24 per cent) and better working conditions (22 per cent).