Haitian officials rejected a Mexican aid ship carrying 77 tons of much-needed food aid because of "unfounded" swine flu fears, Mexico's ambassador said Wednesday.

The Mexican navy ship El Huasteco was to arrive May 2 in Port-au-Prince carrying rice, fertilizer and emergency food kits to help the impoverished country respond to chronic hunger and devastating tropical storms.

But Mexican Ambassador Zadalinda Gonzalez y Reynero said Haitian officials told her April 29 they would not accept the ship, which was still in Mexican waters near the Yucatan peninsula at the time.

"The crew was in perfect health and there was no risk at all," Gonzalez y Reynero told The Associated Press, adding that the cargo and 64 sailors aboard the ship had all been screened in Mexico. "We did not want to turn back the ship, but we also did not want our crew to be mistreated."

She said it was possible the ship could try again to deliver the aid sometime in the future. The shipment is part of the $324 million promised at an April 14 international donors conference held at the Inter-American Development Bank in Washington.

Haitian officials did not immediately confirm the aid refusal. But health ministry executive director Dr. Gabriel Thimothee said all ship crews coming from Mexico must fill out questionnaires to determine if they carry a swine flu threat.

It was not clear if ships coming from the United States are also being screened for swine flu. The new virus has killed 42 people and sickened thousands in 22 countries. But there have been no confirmed cases in Haiti or the Dominican Republic, which share the Caribbean island of Hispaniola.

World health officials are concerned about the potential for outbreak in impoverished Haiti, where three-quarters of the more than 9 million people lack access to medical care.

Haiti is one of 72 "most in need" countries slated to receive antiflu drugs from the World Health Organization. Pan-American Health Organization representatives said the medicine had not yet arrived as of Wednesday.