Workers at the SkyCity casino are having to spray themselves with insect repellent and wear flea collars to keep from being bitten on the job.

Employees have complained about infestations on the casino floor for years and, despite the carpet and areas around gaming machines being cleaned regularly, the problem has persisted.

Unite Union national director Mike Treen said workers had been complaining to SkyCity management, as well as the union, for years.

The last complaint the union received was at the end of last year, during negotiations over pay issues.

"We get complaints about it periodically. There's no recognition that some people are affected more than others," he said. "They have some sort of cleaning process going on. [But] it doesn't seem to be working."

He knew of a number of workers who attached flea collars to their ankles to stop being bitten.

"Some of them have them on to try and prevent being bitten. Some people react quite badly - [they] get really bad spots and it can affect their health and then result in time off. It's definitely a health and safety issue."

Mr Treen said workers were also provided with cans of flea repellent - if they wanted them - so they could spray themselves before starting work.

The union said part of the ongoing problem was that casino management were unwilling to shut the floor down for a day because they would lose too much money. It's just about 24-hour, seven-day business," Mr Treen said.

"They don't want to close the casino down even for a day."

The issue was first highlighted in 2007 when SkyCity said a pest management programme was in place to deal with the infestation.

SkyCity said yesterday that the casino floors were cleaned every day.

Management staff were not aware of any complaints about insect bites.

"Most large carpeted buildings that are frequented by the public encounter some degree of an issue with biting insects," a SkyCity spokeswoman said.

"We have thorough proactive pest control measures in place and are confident that we are providing a safe and healthy facility for our staff and customers."