THE opposition immigration spokesman, Scott Morrison, has defended his use of an international catering and logistics company to provide costings for an asylum seeker centre on Nauru.

Eurest Support Services, known as ESS, was once the largest supplier of food to the United Nations peacekeeping force but was barred as a vendor in 2005 after becoming embroiled in a bribery scandal involving the allocation of UN contracts in Africa.

The ESS parent company, Compass Group, was forced to settle legal action for £40 million with competitors.

A Compass Group Australia executive director confirmed to the Herald that ESS had provided the $95 million costing for the Coalition to build accommodation on Nauru to house 1350 asylum seekers. The quote was a third of the cost estimated by the Immigration Department to reopen a full-service detention centre on Nauru, but the Compass executive said ESS's costing only covered accommodation.

Mr Morrison told the Herald that DeltaFM and ESS were ''all part of the family of companies and all work closely together''.

Company officials flew to Nauru at Compass's expense to provide the Coalition's quote. Mr Morrison said this didn't mean Compass would automatically be granted the contract if the Coalition took government.