Police are excavating a site in Ipswich, west of Brisbane, in the hunt for the body of Sharron Phillips who disappeared 30 years ago.

Ms Phillips vanished after running out of petrol in Wacol, about 10 kilometres from home on May 8, 1986.

While her body was never found, her belongings were located close to her abandoned car.

After a tip-off from a member of the public, who suggested his father may have had something to do with the 20-year-old's suspected murder, police have begun excavating a parcel of land in an industrial estate.

Homicide detectives said it could take up to two weeks to dig up the site in Cobalt Street at Carole Park.

Ms Phillips was last seen about 11:00pm at a telephone box near the Wacol Railway Station, where she twice called a friend asking for help.

Despite several suspects, and a 1988 inquest, no-one has ever been charged over the death of Ms Phillips.

A $250,000 reward remains on offer for anyone who provides information that lead to an arrest and conviction.