MACON, Ga. - Former Telfair County Sheriff Ronnie Walker, who served time in federal prison for protecting marijuana growers, must return to prison by Valentine's Day after he admitted smoking marijuana while on supervised release.

Walker, 58, was ordered to report to the federal prison in Jesup by Feb. 14.

U.S. District Court Judge Avant Edenfield sentenced Walker on Jan. 12 to an additional six months in prison, according to court documents,

In 1994, Walker was sentenced to 10 years in prison plus five years of supervised release after pleading guilty to conspiracy to manufacture marijuana. He was accused of protecting marijuana growers while he was sheriff.

After serving eight years behind bars, Walker was released from prison in 2002. He submitted to a urine test Nov. 8 as a condition of his supervised release, according to court documents. The test was positive for marijuana, and a second test confirmed the results.

Walker at the time "adamantly denied" smoking marijuana, the documents said. He claimed he had been at a fish fry and ate brownies, and asked the probation office if it were possible the brownies contained marijuana.

If Walker had stuck to that story, the judge would likely have sentenced him to a longer period, the court order said. The judge said Walker's "forthrightness" at the hearing led him to reduce the term.

In 1994, Walker told the sentencing judge that when he got out, he wanted to teach law enforcement officers how easily they can be led into "unscrupulous activities." He was among 25 people indicted after an investigation by the FBI and GBI. Walker was sheriff of Telfair County from 1984 to 1992 and previously served as a state senator.