The Government is to give a major boost to the fund launched in memory of four Welsh miners killed at a small colliery.
The bodies of Phillip Hill, 45, Charles Breslin, 62, David Powell, 50, and Garry Jenkins, 39, were discovered at Gleision Colliery in the Swansea Valley on Friday, following a major search and rescue operation.
The men's deaths have prompted a swell of public support for their grieving families - with an appeal fund reaching more than £50,000.
Welsh Secretary Cheryl Gillan said today that the Government would pay the equivalent of Gift Aid on all donations to the charity.
She said: "No-one could fail to have been touched by this tragedy and the response to this appeal is heartfelt.
"When I was at the community centre with the families, I saw, from the outset, local communities donating time, food and assistance to the families and rescue workers.
"Since the terrible events of last week people have donated generously to the appeal fund and I hope they will continue to do so.
"The families have lost working men and the survivors have lost their livelihoods.
"So I am pleased to be able to announce the UK Government will be paying the Gift Aid equivalent of 25% on top of all donations received from the start of the fund.
"This will make a significant difference to the appeal and shows my commitment and that of the UK Government to supporting the fund and those it will support.
The tragedy near Cilybebyll, Pontardawe, unfolded last Thursday when the drift mine's shaft flooded.
Three managed to escape, while four remained trapped.
It had been hoped the miners who were unable to get out might have found refuge in an air pocket following the accident.
However, after a major search and rescue operation, their bodies were found close together - one on the exit side of the blockage and the other three in the area where they had been working.
The deaths prompted an outpouring of grief across the UK, with local Labour MP Peter Hain describing the deaths as a "stab through the heart" of the community.
He launched the Miners Appeal Fund at the weekend, to support the families of the four men.
Mr Hain said the Prince of Wales has agreed to become patron and the fund has so far raised more than £50,000.
In the meantime, two investigations are under way following last week's disaster.
The Health and Safety Executive (HSE) is investigating the cause of the flooding at the drift mine.
A spokesman for the HSE said: "A full report into the causes of the accident is to be published in due course to ensure that any lessons can be applied."
And South Wales Police are looking into a Facebook page, which mocked the fate of the four men killed.
Among the sick comments it carried included: "In a boost to the failing jobs market in South Wales, 4 new vacancies have been created in the Swansea area from Monday!"
This morning, the page appeared to have been removed from the social networking site.
Ian Morgan, a National Union of Mineworkers official based in Rhondda, said: "I hope they catch the people responsible for this as quickly as possible. It is thoroughly sick.
"Whoever is behind this deserves to be arrested and punished in court with the full force of the law."