Spanish collecting society SGAE has again got itself into hot water over its zealous enforcement of its public performance licensing system. This time it has promised to repay in the form of a "voluntary donation" the €5,629 ($7,564) it billed a charity concert arranged by two parents so their gravely ill son could be treated in the United States.

Spanish singing star David Bisbal waived his performing income to headline the concert. But a SGAE employee phoned the mother of Juanma López Fenoy before the concert to ask for a token deposit to cover the copyright. Juanma has an extremely rare degenerative brain disease called Alexander Syndrome, which can be fatal.

SGAE has lost a handful of court cases in recent years for activities such as hiring private detectives to go to wedding parties and make a note of the songs played by the local band performing at the party. Some have blamed SGAE's zeal for boosting public opposition to intellectual property enforcement and legal action against P2P file-sharing.

The concert took place on April 25 in Roquetas de Mar, the south-east Spanish birthplace of the ill boy and also of Bisbal. Saving Juanma's life has become a public issue in the region, and more than €56,000 ($75,47) was raised through ticket sales. SGAE took 10% for authors' rights, and the public outrage was enormous when the case became known.

SGAE published a note that said it had been "absolutely respectful with the intellectual property law... which does not permit any concession to free licences." But it said that in this case, more time would have been needed to locate the authors of songs to be performed to request their permission to waive authors' rights. "In that way, this polemical situation would have been avoided," SGAE said.

SGAE, which has 91,300 members and is the world's fifth largest authors' and publishers' collecting society, added it was making "a voluntary contribution equivalent to the authors' rights charged (€5,629)."

Asturian bagpipe player Hevia, who is also a SGAE council member, said "some things have to be improved in this house [SGAE], and one of them is not to make families suffer as in this case."

Rafael Hernando, the local Popular Party (PP) member of the national Parliament in Madrid, called for changes in the intellectual property legislation. He said this case showed that SGAE was "an authentic band of bloodsuckers, parasites and tax collecting scoundrels."