Court hearing could reveal McCulkin motive

Homicide detectives believe there are still people who have information about the cold-case disappearance of Brisbane mother Barbara McCulkin and her two daughters.

Forty years on, two men, a 76-year-old from Warwick and a 67-year-old from Torbanlea, were arrested on Saturday and charged with the murders of Mrs McCulkin, 34, and her daughters Vicki, 13, and Leanne, 11.

The men were also charged with three counts each of deprivation of liberty and two counts of rape.

Mrs McCulkin and her daughters vanished from their Brisbane home in January 1974.

Their bodies have never been found.

The arrests came after "substantial further evidence" was gathered in what has been a very comprehensive investigation, Detective Superintendent Steve Holahan told reporters on Saturday.

"I believe there are still people out there who have information."

One long-standing theory was the trio was murdered because Mrs McCulkin knew too much about the 1973 Whiskey Au Go Go nightclub bombing in Brisbane's Fortitude Valley, which killed 15 people.

The charged men will appear in the Brisbane Magistrates Court on Monday.

"The investigation looked at all different motives and movements of persons of interest," Det Supt Holahan said.

"We will be leading certain evidence in the prosecution in regards to motive."

In 1980, a coroner recommended two men be charged with the murders, after hearing evidence the pair was seen at the McCulkin home on the night the family was last seen alive.

The charges against the men were dropped in 1981 due to insufficient evidence.

The men arrested on Saturday have not been named but police have said they were known to investigators involved in the case.

Detectives spoke to a number of people in Queensland and interstate in January this year, which led police to a rural property near Warwick in the state's southeast.