The ABC is urging staff at its Melbourne studios to undergo checks after three employees were diagnosed with cancer.

In an email sent to all staff at the broadcasters's Southbank studios, ABC state director Randal Mathieson said management was "deeply concerned" for the health and wellbeing of its workforce.

He said two employees at Radio Australia, on the building's top floor, had been diagnosed with breast cancer.

A third staff member was diagnosed with cancer last year.

Mr Mathieson said the three cases had been referred to Professor Freddy Sitas, who is heading an epidemiological study into breast cancer incidence among ABC employees.

The scare comes less than three years after staff abandoned the national broadcaster's Brisbane studios following the emergence of an unexplained cancer cluster.

At least 17 staff were diagnosed with breast cancer at the Toowong studios in Brisbane's inner west.

In the email sent on Tuesday, Mr Mathieson urged staff who were concerned about the latest cases to seek medical advice and undergo breast screening, which would be paid for by the ABC.

"I am aware that staff have raised the issue of possible emissions from the communications and broadcasting equipment located on the roof of the Southbank building," he said.

"This equipment is regularly assessed for compliance with the general public and occupational reference levels in the Radiation Protection Standard ..."

Mr Mathieson said a hazard control survey conducted in December 2004 found "no hazard exists", except immediately adjacent to equipment on the rooftop and within the main satellite dish area.

In a statement issued late on Wednesday, the ABC confirmed the three cancer cases.

"Our thoughts go out to them and their families at this difficult time," Mr Mathieson said.

"Our primary concern remains the health and welfare of our staff. We have advised them that if they feel concerned, they should seek medical advice from their doctor and undergo a breast screening."

Mr Mathieson said the ABC was expecting a preliminary report next month into the incidence of breast cancer at its studios around the country.

Prof Sitas is undertaking the study for the Cancer Council of NSW.

The ABC has also sought urgent advice from Professor Bruce Armstrong, chairman of an expert panel that reviewed the Toowong breast cancer cases.

The panel was unable to find any link between the work environment and the high incidence of breast cancer.

Prof Armstrong has also been asked to review the ABC's hazard testing system.