Former boxing champ Edwin Valero has committed suicide in his jail cell just hours after he was arrested as part of an investigation into his wife's killing, police said.

The former lightweight champion used his own clothes to hang himself in his cell early on Monday, Venezuelan Federal Police Chief Wilmer Flores told reporters.

He said Valero tied his clothes to a cell bar to hang himself.

He said Valero was found by another inmate, who alerted authorities in the police cell in north-central Carabobo state.

Valero still showed signs of life, but they were unable to save him, Flores said.

The 28-year-old was detained on Sunday on suspicion of killing his wife, the gravest in a string of problems that had threatened to derail his career.

Prosecutors said they had planned to charge Valero in the killing.