A study has shed new light on the mystery of redheads, with eight genes linked to the hair colour discovered by scientists at Edinburgh University.

It was previously believed the hair colour was controlled by a single gene with versions passed on by both parents, however, not everyone carrying two red-haired versions is a redhead, indicating more genes had to be involved.

Sex workers across 33 countries who face repressive policing are three times more likely to experience sexual or physical violence.

Workers are twice as likely to have HIV and other sexually transmitted diseases and experience a higher risk of mental health issues.

Lead researcher and an associate professor in public health epidemiology, Lucy Platt, says repressive police practices increase harms for sex workers, also stating policy reform is needed to improve sex workers' safety.

An internal Border Force email uncovered by the Sydney Morning Herald has exposed plans for the Australian Border Force to save money by removing ships from ocean patrols.

The email detailed operational limitations to be imposed in order to achieve a saving in the annual fuel budget.

In a statement, the Australian Border Force did not deny the fuel-saving tactic but said the Force’s maritime posture was regularly adjusted to remain agile, flexible and responsive to the changing operational environment.

The central bank estimates Australians spend 13.7 billion dollars in the year through August 2017, with methamphetamine and cannabis accounting for over 70% of purchases.

Released Tuesday, a research paper exploring the usage of the nation’s banknotes, suggests almost 2% is used for illegal drug deals, with users still making face-to-face sales.

Excluding cannabis, methamphetamine is the most used illicit drug by weight, followed by cocaine, MDMA or ecstasy, then heroin.

An Infrastructure Australia report released yesterday has shown roads, public transport, hospitals and schools are failing to keep pace with the construction of new housing in Brisbane’s growth areas.

Infrastructure Australia policy and research executive director Peter Colacino says Brisbane needs to focus on growing up instead of growing out and should avoid sprawling out into new greenfield areas.

Presently, Brisbane covers an area 20 times the size of New York City, with only a quarter of its population.