A Laurel County doctor has been sentenced to four years for tax crimes. Authorities say 69-year-old Dr. Werner Grentz of London was sentenced this week by a U.S. District Judge. He received three years in federal prison for falsely reporting his income as $0 on IRS tax documents from 2011-2015. Grentz received another year in prison for violating the terms of his release on a 2013 tax fraud conviction. He was convicted in February 2018. According to evidence at trial, he claimed to make $0 in 2011-2015 when he actually made $726,148 during that time period. The IRS said Grentz owes $237,860 in taxes from that amount. This is not his first conviction for tax crimes. He was convicted of tax evasion in 2014 and sentenced to 18 months in prison for failing to pay more than $900,000 in taxes. Grentz now owes more than a million dollars total in unpaid taxes.