Kenya's prison officers are at the center of an investigation over their involvement in a SMS (Short Message Service) syndicate that defrauded the public through nonexistent lotteries.

Last weekend, 350 mobile phones and 400 unused SIM (Subscriber Identity Module) cards were uncovered after a search of prisoners' blocks at the Kamiti Maximum Prison, and an earlier search at the Naivasha Prison uncovered 270 phones. Officers also found a register bearing the names of potential targets.

The prison department has sought support from the police to conduct the investigation, which began after the public complained of police inaction and threatened to sue mobile phone providers.

People received text messages indicating that they had won money in a lottery. Before any award could be released, however, they were asked to send airtime to a mobile phone number belonging to the fraudsters. After airtime was transferred, the number would shut off, making it hard to trace the criminals.

The cartel's operations were eventually traced to major prisons around the country, but detectives found out that, to succeed, the inmates needed the support of prison officers.

"The prison department will soon install new equipment that will disable mobile phone communication within prison precincts," said the prison department's public relations officer, Dickson Mwakazi, assuring that they have made progress in the investigation.

In the meantime, however, the prisoners have mastered a new hobby: The cartel claims the airtime they've received is sold to people outside prison using the popular "me2u" or "sambaza" method for selling credit on the street.