By Paul Lewis
BBC Radio 4's Money Box
Liberal Democrat MP Steve Webb discovered the new information
Half a million women in their 60s could be due a payout from the state pension of £1,000 or more.
They are women who had not paid enough National Insurance contributions at work to get any state pension.
New figures from the government reveal for the first time, how many women can fill that gap and get their pension.
Most of them will have no idea, that what one MP has called "buried treasure", is waiting for them.
The new information was obtained by Liberal Democrat MP Steve Webb.
His analysis shows that 530,000 of these women could pay one or more years' back-contributions and get a pension.
Gaps in contributions
He told Radio 4's Money Box programme "The typical scenario is: a woman who left school, paid a few years national insurance contributions, got married, spent time at home with children and did not quite have the 10 year's contributions to get any pension at all."
But women who fill the gaps in their National Insurance history could get several thousand pounds.
HMRC National Insurance Deficiency Helpline:
0845 915 5996 (Monday to Friday 8am - 8pm and Saturday 8am - 4pm)
General National Insurance Enquiries for individuals: 0845 302 1479 (Monday to Friday 8am - 5pm)
The Pension Service:
0845 606 0265
or for Welsh speaking customers: 0845 60 60 275 (Mon to Fri 8am - 8pm)
The Pensions Advisory Service helpline:
0845 6012923 (9am to 5pm, Monday to Friday, 9am - 5pm)
"Take a woman of 65.
"It is five years since she turned 60.
"If she can pay contributions to get past the 10 year threshold, she gets a 25% pension.
"That is more than £1000 a year, and backdated for five years that is over £5000"
A woman with a gap in her record for any tax years from 1996/97 to the tax year in which she reached 60, can pay those contributions now, and because of a government concession, the pension will be backdated to her 60th birthday.
Although filling each year's gap costs up to £400, Steve Webb says no money need be found by the women themselves.
"The government just says 'you owe us a few hundred, we owe you a few thousand - here is a cheque for the difference'.
"I call it buried treasure with their name on it, just waiting to be claimed."
Could you benefit?
Not all women in these circumstances will benefit.
A woman whose husband is more than five years older than she is, will probably have had a pension on his contributions since she was 60, and that would normally be worth more than the small pension she could get by paying extra contributions.
Women who have paid the married woman's contribution for many years before reaching 60, may find they cannot pay enough full contributions now.
And those who claim means-tested benefits will find some of that money is clawed back.
But Steve Webb says any woman in her 60s who does not get a state pension should take action.
"It is always worth making a call to the National Insurance or pensions people simply asking, could you benefit.
"Are you owed several thousand pounds, or could you get a boost to your pension?"
BBC Radio 4's Money Box was broadcast on Saturday, 6 October 2007 at 1204 GMT.