Jerome Kerviel, the former trader at French bank Societe Generale accused of making unauthorized trades that cost the firm billions of euros may have been helped by someone inside the company, according to a report released today.

The report published by the bank on Friday also said supervision of the trader was weak and that poor control systems were to blame. The report was carried out by three non-executive directors at the bank.

There are indications that an assistant trader in the bank's middle office was linked to Kerviel's actions, helping to hide his transactions.

We have discovered indications of internal collusion involving a trading assistant, a Middle Office operational agent dedicated to [Jerome kerviel's activity, the report stated.

The bank said that due to a current on-going criminal investigation, the bank has not been able to question the person on the subject.

The possibility of such internal collusion must therefore be confirmed by the courts, the report stated.

The report stated that an electronic message appears to establish that the assistant was aware of the earnings made by Kerviel on the allegedly fraudulent trades.