A plan to fight the mosquito that spreads Zika and other illnesses by releasing genetically modified versions of the insect in the Cayman Islands has been put on hold following a court challenge.

The Cayman mosquito control unit was going to start releasing GMO mosquitoes produced by British biotech firm Oxitec last week. A government statement announced the delay Monday.

Arguments are expected Tuesday on whether to extend a temporary injunction until a court can conduct a formal review of the project sought by opponents.

Plans call for releasing millions of modified male mosquitoes of the species Aedes aegypti. Males don't bite but would mate with females and produce offspring that die before reaching adulthood. Opponents say they have not been given enough information on any potential risks.