The BBC's Angus Roxburgh interviewed Paul van Buitenen in Brussels

Paul van Buitenen, a Dutch member of the Commission's financial control unit, was suspended on half-pay in December after sending the European Parliament a damning report alleging fraud was more widespread than previously acknowledged.

Mr van Buitenen says he found evidence of a cover-up by senior colleagues.

"I found strong indications that there have been actions for cover-up, that auditors have been hindered in their investigations and that officials received instructions to obstruct the audit examinations," Mr van Buitenen says in a BBC interview.

"The Commission is a closed culture and they want to keep it that way, and my objective is to open it up, to create more transparency and to put power where it belongs - and that's in the democratically-elected European Parliament," he says.

The Commission says he was suspended for breaking his contract by releasing details of the inquiry.

Martine Reicherts, spokeswoman for the European Union's executive body, said the report should have been kept secret while the case is under investigation.

Angry MEPs

Members of the European Parliament have strongly criticised the Commission's sanctions against Mr van Buitenen.

MEPs demand explanation for the suspension

The Green group said it would ask the Finnish EU Budget Commissioner Erkki Liikanen this week about the reasons for the suspension.

"It is striking to note that the harshest sanctions have been taken against Paul Van Buitenen. Since December 18 he has been suspended from his job and no longer has access to his office. His salary has been reduced by half," the Greens said in a statement.

British Conservative MEP Edward McMillan-Scott has demanded the resignation of Mr Liikanen.

"To make a scapegoat of someone doing their public duty shows that the Commission is in a state of panic," Mr McMillan-Scott said.

"Liikanen's attempts to reform the Commission have badly failed. The only way to highlight this would be for the EU Commissioner responsible to fall on his sword."

No-confidence motion

Mr van Buitenen's report was one factor which led the parliament's assembly to refuse to approve the EU's 1996 accounts on 17 December and table a no-confidence motion in the Commission.

That vote, which could lead to the sacking of the 20 Commissioners, is scheduled to take place during the assembly's regular monthly sitting in Strasbourg next week.

In recent months, the Commission has faced repeated allegations of mismanagement of the EU aid budget and the hiring of staff through outside consultancies or contractors.