Two Queensland men have been charged with the murders of Brisbane woman Barbara McCulkin and her two daughters who disappeared 40 years ago.

The men, a 76-year-old from Warwick and a 67-year-old from Torbanlea, face three counts each of murder and deprivation of liberty and two counts of rape, police say.

The pair were arrested on Saturday morning and are due in the Brisbane Magistrates Court on Monday.

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In one of Queensland’s most baffling cold cases, Barbara McCulkin, 34, and her two daughters, Vicki, 13, and Leanne, 11, disappeared from their Brisbane home in January 1974 and haven’t been seen since.

Detective Superintendent Steve Holahan says the arrests are a result of years of hard work by many investigators and specialist officers.

“It’s extremely pleasing, particularly for the investigators,” he told reporters in Brisbane on Saturday.

“It’s very satisfying, it’s been a very intense, relentless investigation.”

Det Sup Holahan wouldn’t say specifically what lead to the arrests but said a number of people from Queensland and interstate had provided new information about the case since it was reopened in January.

He says a possible motive for the alleged killings will likely be presented in court on Monday.

The family of the alleged victims have been offered support and have told police they’re grateful charges have been laid.

Det Sup Holahan believed there were still a number of people who had information about the case who were yet to come forward.

The case was reopened in January and a number of Crime and Corruption Commission hearings into the suspected murders were held over 31 days from February this year.

Police spoke to a number of people in Queensland and interstate and raided three properties near Warwick following a review of the case.

The men haven’t been named but police have said they were known to homicide investigators involved in the case.