Missing US rapper Brian Trotter has been found dead in his friend's truck.

The musician was found on Sunday by cops after the rapper's pal Robert Avery Coltrain, after he got into a collision on a highway in Miami Florida around 4pm.

According to cops they pulled his body from the boot after smelling a "foul smell".

Cops say flies were buzzing around his body when it was discovered on a highway in  Miami, Florida, by state troopers.

Coltrain is said to have removed some belongings from his car when encountered by cops – including a Glock .45 pistol,  according to WTVJ.

Coltrain was charged with second-degree murder and illegal transport of human remains

Trotter’s body was “wrapped in a piece of fabric and in an advanced stage of decomposition”, according to the police report.

Investigators believe the Glock .45 pistol recovered from the car was used to kill the aspiring rapper. 

Coltrain, 25, picked his son up from his home in  Triangle, Virginia, on October 17, Trotter’s father, Brian, said.

The musician was found on Sunday by cops who encountered the rapper's pal Robert Avery Coltrain

Brian said the pair had planned to “take pictures” in nearby Washington, DC.

The dad told The Miami Herald: “I told him, ‘I love you,’ and he said, ‘I love you.’”

After the rapper's family reported him missing to police, they say they spoke Coltrain -  who they alleged gave conflicting information on his whereabouts.

He allegedly said he dropped Trotter off in Washington DC where another friend picked the rapper up.

It is thought at some point, Coltrain apparently drove to Florida, where he got into the accident.

Coltrain was charged with second-degree murder and illegal transport of human remains and is being held without bond at the  Miami-Dade jail.

Trotter’s father said “no one can understand what happened".

He added: "Hopefully, police can shed a light on what made a friend of over 10 years decide to commit something like that.”

According to a postmortem, Trotter was shot multiple times in his torso.

Trotter was reportedly shot "at least once inside the car with the Glock".

Police are looking into a motive for the killing.