Coppers have sent out a message for computer developers hired by criminals – you could face conspiracy charges.

Two computer developers have been arrested by the FBI for allegedly cooking the books for Wall Street conman Bernard Madoff. Jerome O'Hara and George Perez, who worked for Madoff from 1990 and 1991 respectively, were arrested and could face 30 years inside. Both have been charged with conspiracy and falsifying accounts.

Prosecutors claim that O'Hara, 46, and Perez, 43, are accused with being core players in a scheme that defrauded thousands of investors. However what it seems the pair did was run programs on an IBM server known to employees as "House 17". The code generated false accounts and records, which fooled at least five probes between 2004 and 2008 by the US Securities and Exchange Commission.

Both knew that the code they wrote was up to no good and had a rebellion against Madoff in 2006. They met with Madoff and told him, in substance, that they would no longer lie for him. Madoff ordered his right-hand man: "to pay O'Hara and Perez whatever they wanted in order to keep them happy".

They were paid a bonus of $60,000 and were given pay increases.