Notorious BIG's last album, Born Again, was released in 1999

It follows the FBI decision in March to close its investigations into the 1997 killing of the rapper.

A case against Los Angeles city authorities will continue, the family of the 24-year-old performer said.

The FBI had been looking into a theory that a rogue police officer was involved, but decided there was not enough evidence for a prosecution.

Notorious BIG, real name Christopher Wallace, was shot dead six months after the killing of rival Tupac Shakur.

There have been reports that the murders of both Notorious Big and Shakur were part of a US rap feud, but both remain unsolved.

Court papers filed on Friday dropped former officer David A Mack from the wrongful death action, but offered no explanation.

'Police involvement'

The Los Angeles Times reported that lawyers for the Wallace family were also to drop their case against Amir Muhammad, who was accused of being the gunman in the murder.

It would leave the city of Los Angeles as the sole defendant.

Notorious BIG, also known as Biggie Smalls, was regarded as one of rap's brightest stars, with gritty lyrics about street life, when he burst onto the scene in 1994.

Wallace's relatives are suing the Los Angeles Police Department for allegedly covering up police involvement in the singer's death.

The case, led by the rapper's mother Voleeta Wallace, is scheduled to go to trial in Los Angeles on 23 June.

Suge Knight was never named as a defendant, but the legal action accuses him of ordering the killing.

"This is a civil rights case against the city of Los Angeles," said Perry Sanders, who represents the Wallace family. "This has always been a case against the city."