The European Union has launched an investigation into whether Channel 4 should receive a £14 million (€17.7m) injection to pay for the cost of upgrading to digital broadcasting.
The European Commission has said it has “serious doubts” that the costs incurred would justify receiving public money.
The funding would be drawn from the BBC licence fee.
It has emerged that the EU received a complaint from another British commercial broadcaster that claimed Channel 4 had sufficient cash reserves.
Broadband TV News has long made the point it was curious that Channel 4 required £14 million funding for digital TV when it was able to find £28 million for a 50% stake in the EMAP music channel business.