ONE of the United States' top investigators of illegal immigration has been reassigned from Hong Kong at the start of the alien smuggling ''sailing season'' and will not be replaced for at least six months. Jerry Stuchiner, the officer in charge of the Immigration and Naturalisation Service (INS) in Hong Kong until last Friday, flies back to the US today. The task of providing intelligence on illegal immigration now falls on the shoulders of Jim DeBates, who will be operating on his own until October, when a replacement for Mr Stuchiner is due to arrive. The delay is believed to be due to ''economic problems'' within the INS, which is expected to post a deficit of US$40 million (HK$308 million) this year. Mr Stuchiner, who is believed to have set up a considerable intelligence network in China, Taiwan and Hong Kong in his five years at the US Consulate, is being posted to a new station in Honduras. Because of the personal and sensitive nature of the network, it is unlikely any of these contacts will be passed on, causing concern among some US and Hong Kong officials. Mr Stuchiner would not comment on the move other than to confirm he was being sent to Honduras to set up a new INS post. His reassignment comes as the Jin Yinn #1 is on its way to Guatemala under US Coast Guard escort, and two other suspected smuggling vessels are heading for the US from Guangdong. According to a Washington source, Mr Stuchiner is one of the best alien smuggling investigators there is and his eventual successor will not be able to carry on the work at the same level or with the same results. The source described him as a bit of a loose cannon who used his own methods, and said he was being moved because of ''internal politics''. He said Mr Stuchiner's departure would seriously damage the fight to stop the flood of illegals. ''The Hong Kong office is a critical post for alien smuggling investigation,'' the source said. ''There's no question about that. It's very important, if not the most important overseas post for gathering intelligence. ''Stuchiner was a very active force in Hong Kong,'' he said. ''He had a high visibility and some real strengths. He was very sincere in trying to do something and gets A-plus for his 'go-get-'em' attitude. ''But the way he went about it was in some ways unorthodox. He had some weaknesses and stepped on some toes, and I think that's got something to do with it.'' A spokeswoman for the US Consulate in Hong Kong last week said the timing of the move, at the start of ''sailing season'', was ''unfortunate''. ''This is a very important issue,'' she said. ''He has done a great job and we will miss him.'' The INS has been criticised since the flood of illegal Chinese immigrants first made headlines when 524 illegals were found on the East Wood when it broke down on its way to Hawaii in January last year. In a leaked report the following month, the Washington Post quoted from a confidential memorandum from Jim Hays, an assistant district director at the INS office in Los Angeles, who claimed his hands had been tied by Washington bureaucrats.