Investigators on Thursday found some medicines, liquid and tablets in bags belonging to Rachadech Wongthabutr, a 24-year old freelance male model, in connection with the death of Thitima "Lunlabelle" Noraphanpiphat, a 25-year-old commercial presenter.

The tablets appeared to be Viagra and a mixture of so-called "date rape" drugs which investigators believe Thitima consumed or was given shortly before her death.

The source added investigators are attempting to figure out if Thitima took any pills before she died, and if so whether they match those found in Mr Rachadech's bags. They are also thought to have found pills at a home in the Bang Bua Thong area where Thitima attended a party before she was found dead.

Meanwhile, the police are looking into details about the home, where parties were held frequently, said the source.

When questioned, the owner of the house claimed he earned a living by trading on the stock market, a statement investigators do not fully believe.

The police are running background checks on all people who may have something to do with the death of Thitima.

Police promised on Thursday to answer all key questions relating to her death within two days.

Thitima's body was discovered on a sofa in a condo lobby in Bangkok's Thon Buri area early on Tuesday morning.

The investigation is about 80% complete as investigators are still waiting for some documents including results of the autopsy as well as DNA tests on both Thitima and the prime suspect Rachadech Wongthabut.