Killer whales are suspected to be responsible for the disappearance of great white sharks off Cape Town's coast over the last few years, according to a report published by South Africa's government on Tuesday.

The disappearance of great white sharks from the coastal sites False Bay and Gansbaai had previously been blamed on illegal hunting and overfishing, among other causes.

But results of a study conducted by a government-appointed team of nine local and international experts suggest that orcas could be responsible, after a pair of killer whales was first sighted in the area in 2015.

The researchers said they "found some evidence for a causative link between the appearances of a pod of orcas that had specialized on preying on white sharks".

The number of great white sharks in the area is not known, but spotters initially reported steep declines in 2017, then an extended absence.

Great white sharks are a big tourist attraction in South Africa. They are seen from boats or from cages lowered into the water.