By JULIET WILLIAMSSACRAMENTO, Calif. (AP) â¿¿ State employees engaged in bribery, conspiracy to commit mail fraud, received improper overtime payments and were wrongly reimbursed for thousands of dollars in travel expenses, including one scheme that cost two state agencies more than $227,000 in lost payments, California's state auditor reported Tuesday. In her annual whistleblower report, state Auditor Elaine Howle said her office received 7,238 reports of improper activity from April 2011 through the end of June 2012 and has opened investigations into nearly 1,500 cases from that time and before. The state's whistleblower act authorizes her office to investigate improper and illegal government activity that is wasteful or involves gross misconduct, incompetence or inefficiency. In the biggest case cited this year, Los Angeles employees of the Franchise Tax Board and secretary of state's office collected thousands of dollars in payments from a courier in exchange for supplying him with hundreds of official state letters for his clients without charging the $15 to $20 per letter fees, the report said. All three were convicted of bribery and ordered by the Los Angeles County Superior Court to pay more than $227,000 in restitution for the ruse that occurred from at least 2007 to 2009. The report said at least one other employee knew about the scheme and lied to investigators, while another quit. One staffer was sentenced to sevenÂ days in county jail, 400 hours of community service and four years of probation, and a second to three years' probation and 400 hours of community service. The courier was sentenced to 14 days in custody, six years' probation and 200 hours of community service. The auditor's report also found that a "high-level official" in the University of California president's office was wastefully reimbursed for $6,100 in travel expenses from July 2008 through July 2011, including for a five-day trip to England, even after she highlighted wasteful reimbursements to the man totaling more than $152,400 when he worked at the California State University chancellor's office.