The directors of Farepak, the Christmas savings club that collapsed in 2006 leaving thousands without a penny, could face prosecution, the Consumer Minister suggested yesterday.

An investigation by the Companies Investigations Branch (CIB) of the Department for Business, Enterprise and Regulatory Reform is complete and ministers are taking advice on whether a prosecution can be mounted.

To the anger of MPs who campaigned on behalf of customers who lost their Christmas savings, the report will not be made public ahead of any legal action.

In a written ministerial statement, Gareth Thomas said that the CIB was taking advice on whether its evidence warranted legal action and promised the findings would be published if a court case went ahead.

He said: "If proceedings are taken against any party involved, this will become public knowledge if or when the case reaches open court.

"We will do everything in our power to process this quickly."

The investigation had taken longer than expected because it involved gathering information from Farepak and other companies which were in administration.

Mr Thomas added: "The report is over 700 pages long and could lead to court proceedings, so taking short cuts in the investigation was not an option."

Meanwhile, the liquidators of the company are to sue the former directors to obtain more money for the Farepak creditors.

Some 150,000 families lost about £40 million savings when the Swindon-based firm went into administration in October 2006. Creditors, including customers, are expected to get about 5p in every pound returned.

Jim Devine, the Livingston MP who was at the forefront of the consumer campaign, said he would be "very surprised" if there were no prosecutions as a result of the collapse and called for the report to be published in full.

Mr Devine said: "It is totally unacceptable - 123,000 families were affected by this and people have a right to know what has happened to their money."