URUAPAN, Mexico (AP) _ Investigators are trying to determine whether Israeli counterterrorism expert Amiram Nir was really interested in avocados during a visit to this backwater town that ended with his death in a plane crash.

Nir, who died Wednesday, was not known as an avocado exporter. He had advised two Israeli prime ministers on terrorism and was linked to the Iran- Contra deal that embarrassed the Reagan administration.

Avocado grower Carlos Garcia Mendez and a police official said Nir stayed in the best hotel, discussed avocado prices and inspected an avocado processing plant during a three-day visit to this town nearly 200 miles west of Mexico City.

''It was his destiny to die here,'' was the only explanation Mendez could offer Sunday in an interview.

Staffers at the Hotel Real de Uruapan said Nir was traveling with a man who registered as a Lebanese and left before Nir did.

The wife of the owner of Aerotaxis of Uruapan, Marta Amezcua, said Nir and Adriana Stanton, a Canadian woman who was working for an avocado operation, chartered a small plane on Wednesday.

The Aerotaxis plane crashed near Ciudad Hidalgo, killing Nir and an airline employee and injuring Ms. Stanton and the pilot, Amezcua's son.

A security guard stands outside the room where Ms. Stanton is hospitalized in Mexico City. Ms. Stanton, who suffered leg, arm and facial fractures, has refused to speak to reporters since Thursday, when she said she barely knew Nir.

No one can explain why Nir, who registered under his own name at the hotel, apparently gave an assumed name when he chartered the aircraft.

Israeli officials and friends' of Nir's in Israel said he was in Mexico on business, but they refused to say what the business involved.

Garcia Mendez is a partner in Eupasa, a six-month old business that is trying to export avocados to Europe through Nucal, a Swiss firm. He said his operation grows about 500 tons of avocados a year.

Mexico has been looking for expanded export markets for agricultural products such as avocados.

Garcia Mendez said Nir dealt mostly with Pedro Curchet, an official of Eupasa in charge of quality control. He said Ms. Stanton was in charge of shipping arrangements for Eupasa.

Curchet was the man who went to Ciudad Hidalgo and identified Nir's body, according to federal judicial police commander Jose Luis Arriaga. Curchet said Nir had planned to return to Uruapan in a week, possibly to close a deal with Eupasa, according to Arriaga.

Arriaga said he had no evidence Nir's visit involved anything but avocados.

Hotel personnel said Curchet and Stanton had been in Uruapan since September, which is when the avocado harvest begins.

Eupasa employs about 50 people in its packing operation, and other avocado growers in the area recently formed a competing organization, the Association of Producers and Exporters.

On Sunday, The Washington Post quoted Nir as saying in an interview earlier this year that counterterrorist operations he supervised in 1985 and 1986 with former White House aide Oliver North were authorized by a secret agreement between the United States and Israel.

Israel denied the report. Secretary of State George Shultz, asked if such an agreement ever existed, said: ''Not that I know of.''