XXXTentacion was expecting a baby with his girlfriend when he was murdered, the star's mother has confirmed.

"He left us a final gift," Cleopatra Bernard wrote on Instagram, next to an ultrasound picture of the unborn child.

The news was later confirmed on the rapper's personal account, with the message: "May the new baby know his father was a legend."

XXXTentacion, real name Jahseh Onfroy, was shot outside a motorcycle showroom on Monday and died later in hospital.

Authorities said the rapper was ambushed by two suspects in an apparent robbery attempt.

A suspect, named as Dedrick Devonshay Williams, was arrested on Thursdayand faces a charge of first-degree murder.

"Homicide detectives are seeking additional suspects," said Broward County Sheriff's Office. "The investigation continues."

He left us a final gift.

A post shared by @ cleo_ohsojazzy on Jun 21, 2018 at 1:55pm PDT

XXXTentacion's lawyer, J David Bogenschutz, told People magazine his family "will be much calmer as soon as it is confirmed that all of the suspected participants are in custody".

The musician was one of the fastest-rising artists in the US, after breaking out with the bratty, distorted song Look At Me! in early 2017.

But at the same time as his career took off, the musician was in jail, after being arrested on charges including aggravated battery of a pregnant victim and false imprisonment.

He was awaiting trial on those charges at the time of his murder.

The identity of his unborn child's mother is not known, but it is not thought to be Geneva Ayala - who filed the original charges against him.