Big tobacco has exploited a loophole in Australia's world-first plain-packaging laws, which allowed smokers to ditch the now famous drab packaging.

The Department of Health has received 1054 individual complaints involving 746 cases since the December 2012 legislation banning tobacco companies from putting their products in anything other than dark olive brown packaging that feature graphic health warnings.

Plain packaging laws in Australia are some of the toughest in the world. Credit:Nic Walker

Of those cases, 459 were cleared and 135 warning letters were issued, according to figures revealed in a Senate estimates hearing on Wednesday, with an ACT retailer receiving the only fine, paying $2040 for "non-compliant cigars".

But the department could not say whether Imperial Tobacco, one of the world's biggest tobacco companies, received a warning for producing what it described as a "fresher, premium product" for its Peter Stuyvesant brand which allowed customers to shed the government-mandated packaging and use a plain silver soft pack enclosed inside.