A Labour MP is calling on legal firms who have charged miners for compensation work to refund the money.
The fund is one of the world's largest personal injury schemes
Bassetlaw MP John Mann said he has had almost 1,500 complaints from miners in his constituency alone about legal firms charging "twice" for their work.
Under a government scheme, miners with industrial illnesses are compensated, and have their legal fees paid.
Mr Mann said his campaign will continue "until every miner and every widow gets every penny of their compensation".
One legal firm has already decided to refund fees charged to miners for work on the compensation scheme.
Hopkins Solicitors in Mansfield has already paid back the fees.
One of the firm's solicitor, John Bates, told the BBC East Midlands Politics Show: "We felt it was morally the right thing to do in the circumstances."
Mr Mann said: "I am fighting cases for miners to get their money back because it should never have been deducted in the first place."
"They were never told that the government has paid all the solicitors' costs - so this is money for nothing.
"Let's see every firm of solicitors firms that have deducted money from miners and miners' widows for industrial injury - sick and elderly miners - let's see them pay back the money."
£8bn paid out
In a separate development, the Serious Fraud Squad raided offices and homes in Mansfield, Nottinghamshire earlier this week as part of a probe into the handling of compensation claims.
The Union of Democratic Miners formed a separate firm called Vendside - whose premises in Mansfield were raided last week - to handle compensation claims.
Vendside said the raids had nothing to do with its claim-handling agreement with the Department of Trade and Industry and added it "had nothing to hide".
The DTI has paid Vendside to handle claims and the firm has already secured more than £158m for 29,000 miners and their families.
The government has already paid out £8bn under the scheme to 750,000 miners and their families since 1999, in one of the largest compensation agreements in the world.