The ABC will apologise to its viewers and review its science program Catalyst after an independent investigation found a controversial episode on the potential health risks of Wi-Fi that went to air earlier this year breached its editorial standards.

The damning finding - which will see reporter Maryanne Demasi suspended from on-air assignments until at least September - comes two years after a similar investigation slammed a Catalyst program questioning the use of cholesterol-reducing medications.

As with the earlier program on cholesterol, the Wi-Fi episode will be removed from the internet.