Otago Museum management have rejected allegations large numbers of tropical butterflies have escaped from their tropical forest enclosure since it opened in 2007.
Museum exhibition, development and planning director Clare Wilson said the claims were "a storm in a tea cup".
She confirmed up to 20 butterflies escaped in September 2007 before the exhibit opened to the public, and were found on a pathway at the rear of the museum.
"But that's the only significant escape we know of. We've had one or two [butterflies] escape now and then because they go out with people - they land on them and get carried out accidentally."
There were about 1000 tropical butterflies in the exhibit at any one time, she said.
While the butterflies had the potential to be a bio-hazard, they were not a threat because they died as soon as they left the heated environmental enclosure.
There had been no significant butterfly escapes from the museum since the Tropical Forest Exhibit opened.
"We take the escapes very, very seriously. We searched with a fine-toothed comb looking for areas that the butterflies may have escaped.
"Several hours were spent sealing the escape routes."
Ms Wilson said escapes were logged because it was a requirement of the museum's permit.
She confirmed the Ministry of Agriculture and Forestry threatened to close the exhibit in September last year when a member of the public phoned the Maf bio-security hotline to report a dead tropical butterfly outside the museum.
When Maf inspected the escapes log and found 30 butterflies had escaped, they threatened to close the exhibit.
"But when they realised it was 30 over a 12-month period, and that many of the butterflies had only escaped into an adjacent gallery at the museum, they were satisfied that there was no bio-security risk."
