TEHRAN, Iran (CNN) -- A trip to find a former FBI agent who is missing in Iran is almost over, "and the miracle we were hoping for has not happened," his wife said Saturday.
Robert Levinson disappeared in March after a business trip to Iran.
"We still don't know were Bob is, and the nightmare that I and my family are experiencing will continue," his wife, Christine Levinson, said at a hotel in Tehran. "I cannot express in words the pain we are feeling and the depth of our disappointment."
Robert Levinson was last seen March 8 on Iran's Kish Island in the Persian Gulf.
"We have no information to confirm [Levinson is in Iran], though they [Levinson's family] can inform us about any traces and information they may have and we will welcome that," Gholam Hossein Elham, a spokesman for the Iranian government, said Saturday.
Christine Levinson wrote to the Iranian government in September asking for permission to travel in Iran. That permission was granted, although the government said at the time that it had no evidence that her husband had even been in Iran, despite "every effort to find any clues as regards Mr. Levinson's case."
She said at the time that the claim appeared to contradict information the government had given the Swiss Embassy that Robert Levinson was seen leaving a hotel on the island March 8. The Swiss handle U.S. affairs in Tehran because the United States has no diplomatic relations with Iran.
Christine Levinson, accompanied by the couple's son, Daniel, 22, thanked Iranian officials who met with them. She also thanked the Iranian people -- particularly hotel staff and airport workers on Kish Island.
"When we told them why we are here and showed them a photograph of Bob and our grandson, they were extremely sympathetic to our situation," she said. "It means a great deal to us."
Christine and Daniel Levinson arrived in Iran on Tuesday and are scheduled to leave Sunday.
Robert Levinson, 59, reportedly was on Kish to investigate a cigarette smuggler for a client of his security firm.
In June, President Bush said he was "disturbed" by the lack of information Iranian officials had provided on the case. E-mail to a friend