Sydney, Sep 2 - Secret Soviet whaling between 1947 and 1973 wiped out some humpback whale population in the Pacific, according to a new study.

Wally Franklin, doctoral student at the Sydney based Southern Cross University's Whale Research Centre and co-director of The Oceania Project, co-authored the paper.

While it had been known that almost 100,000 whales had been killed secretly by the Soviet whaling fleet in the southern hemisphere, it had not been clear how this had impacted the current humpback whale population, Franklin said

'It was always a mystery why the population of humpback whales off the east coast of Australia and in the Pacific region suddenly collapsed in the early 1960s,' Franklin said.

'This new study has shown the link between the illegal catches during the late 1950s and early 1960s and the collapse of the Australian and Pacific populations.'

During the 1950s the whaling stations at Tangalooma (in Queensland) and Byron Bay each had a quota of whales which they could usually get in a couple of days.

'By the early 1960s, all of a sudden they just couldn't find any whales to meet the quotas and basically the industry collapsed,' Franklin said.