Waiter Admits He Did Cocaine with Liam Payne, But Refused Payment

Prosecutors want to file charges related to Liam Payne‘s death admits he used cocaine with the singer … but insists he didn’t get paid and was NOT a drug dealer.

Brian Paiz told us in our upcoming documentary, TMZ Investigates. Liam Payne: Who’s to blame?” — Monday night air 8 PM ET on FOX — she organized a party with Liam in the singer’s Buenos Aires hotel room.

Paiz says they drank whiskey and used cocaine he brought to the hotel. He says they did it twice…the second time was just 2 days ago Liam’s fatal fall from the balcony of the hotel.

Brian says he saw drugs strewn everywhere … along with a box of Dove soap and tin foil, which are widely seen in photos taken after Liam’s death.

Bryan says he never accepted money from the singer … and claims he even turned down Payne’s Rolex watch when the star offered it as payment.

There’s one gift she took from Liam, Paiz says … watch the clip and hear what memo she got.

Paiz is one five men Prosecutors are investigating Liam’s death.

So do we interviewed a close friend of Liam’s Roger Norris— who prosecutors accuse of abandoning Liam and supplying drugs — and a witness Brett Watson … who saw Liam die.