A Thai-born student at American University, who boasted of receiving pure white Asian heroin in packages sent through the Royal Thai Embassy in Washington, has been sentenced to Montgomery County Circuit Court to five years in jail of conspiracy to sell heroin.

Suwannawat Thongtham, 26, of 3138 N. 10th St. in Arlington, who recanted the boast, could have received a maximum 20-year sentence on the charge. Thongtham, a graduate student in chemistry, will face deportation proceedings when he is released from prison.

Assistant state's attorney Tom Heeney had asked Judge H. Ralph Miller to sentence Thongtham to a maximum term, describing the stocky, blue-jean-clad defendant as "a major drug dealer . . . strictly a businessman who was (dealing drugs) for only one reason - to make a profit."

Judge Miller, despite his stating that he accepted the prosecution's contention that Thongtham reaped $14,000 from 88 drug transactions in 14 weeks before he arrested last year, cited American Bar Association sentencing standards as his reason for imposing the five year sentence.

Thongtham, who has been in jail since his arrest last May 13, will be eligible for parole in six months. If paroled, he would immediately face deportation proceedings for having been convicted of a crime, officials of the Immigration and Naturalization Service said.

Thongtham had pleaded guilty to the conspiracy charge in November, making a trial unnecessary.

However, in a legal procedure which allowed the prosecution to state its case against Thongtham, Montgomery County police vice officer Ronald A. Ricucci testified that Thongtham received the high-quality heroin concealed in tape cassettes and ornamental seashells sent to an aunt at the Royal Thai Embassy.

The packages were "stored" at the embassy until Thongtham picked them up, Ricucci said.

Thongtham, who had been in the country on a student visa since 1972, then sold the heroin at a pace of $1,000 a week to three distributors. The distributors in turn sold the drug to a group of 25 addicts in the Twinbrook section of the county. Ricucci testified.

Ricucci later told a reporter that he didn't know the name of the alleged aunt, but had relied instead on three witnesses who independently repeated what Thongtham had told them. Embassy officials denied any knowledge of Thongtham and said the heroin couldn't have come through the embassy's diplomatic pouch.

Thongtham, when Miller asked him if he wanted to make any statement before sentenced, said he had made up the story that he had relatives or friends in the embassy "to make me look important." He said he bought the heroin in Washington.

However, moments before, Ricucci, whom Henney recalled to the witness stand in an effort to convince Miller that Thongtham deserved a long jail term, testified that police officials had tested the heroin and found it to be 25 per cent pure, an unusually high quality. Ricucci said the powder was of Asian origin.

Thongtham's arrest and the prosecution's case was based on information from a man who had purchased heroin from Thongtham on 18 separate occasions before having a falling out with him. The man was granted immunity from prosecution.

The man abducted Thongtham last April 16 and tied him to a tree in the Turkey Run section of Fairfax County near the George Washington Parkway in order to ransack Thongtham's Arlington apartment.

The man turned over to police $7,000 worth of heroin and a ledger book containing information about the heroin sales, Ricucci testified. He said a handwriting expert had certified the handwriting in the ledger book as that of Thongtham.

Although Thongtham lived in Arlington, conspiracy charges were brought against him in Montgomery County because that is where the sale of heroin took place.

Thongtham's three distributors were also charged with conspiracy to sell heroin. One, Keith Hicks of 13209 Midway Ave. in Rockville, was sentenced last week to six years in prison. The other two, Dean Harris, of 24-C Crestwood Ter. in Gaithersburg, and William Harrington of 9 Tapiola Ct. in Rockville, have pleaded or will plead guilty soon and be sentenced, Henney said.