Washington, July 18 - An Indian-American doctor couple in Houston has been charged with illegally distributing 1.3 million tablets of a drug and defrauding several public and private health insurance companies of $31 million by filing false claims.

According to the indictment returned by a federal grand jury Thursday, Dr. Arun Sharma and his wife, Dr. Kiran Sharma, both 54, operated the Allergy, Asthma, Arthritis and Pain Centers located on Cole Street in Webster, Texas, and another on Garth Road in Baytown, Texas.

The indictment alleges that Dr. Arun Sharma routinely saw in excess of 70 patients per day and that he routinely wrote prescriptions for hydrocodone that were not for a legitimate medical purpose in exchange for cash payments, the Federal Bureau fo Investigation said in a press release.

Dr. Sharma allegedly received the cash payments for his hydrocodone prescriptions directly from the patient and he instructed his patients to take the prescriptions to certain pharmacies to be filled.

Arun and Kiran Sharma, according to the indictment, stored large amounts of cash received from the sale of hydrocodone prescriptions at their home. Kiran Sharma allegedly transported large amounts of cash received from the sale of the hydrocodone prescriptions to two safe deposit boxes - one each at Bank of America and Prosperity Bank.