For almost three years William Kyle worked on the widening of the Capital Beltway in Virginia, driving a truck for Excavation Construction Inc. and taking home $113 a week in pay, barely enough to support his family of five children.

Each month $9.50 was deducted from his paycheck to cover his dues for membership in Teamsters Local 639. That dues money, some $350, has all but disappeared. It was never credited to Kyle at the union and Kyle says he never received a refund from the construction firm.

Kyle's money is part of the $40,000 in dues that newly elected Local 639 officials estimate is missing because of a confusing series of fund transfers between Excavation Constructions Inc. and former president of the local. The mystery grew out of an unusual union contract signed for the beltway project, a contract that is a key aspect of the current federal grand jury investigation into alleged labor-management racketeering in Maryland.

What happened to that money? According to an internal memo of the International Teamsters, the dues for all the Local 639 workers on the beltway were sent back to Excavation Construction Inc. to be refunded to the workers. Excavation Construction Inc. officials refuse to comment.

After a three-week search of payroll records, union records and interviews with more than 30 of the affected beltway workers. The Washington Post could not find any worker who said he had received a refund of his dues.

However, the dues of at least six of these workers were received by the union treasury. Union and payroll records show that not all the union dues were returned to Excavation Construction Inc., contrary to the findings of the Teamsters memo.

The beltway contract is one part of the continuing investigation by the Maryland U.S. attorney's office into an alleged pattern of favors between former Teamsters officials and the corporate heads of major firms in Baltimore and Washington. As a result of this investigation. Giant Food Inc. pleaded guitly last week to making illegal payments to a union official to keep union peace.

Although the union official was not named during the court hearing for Giant Food Inc., the only man who could fit the description is Frank DeBrouse, the former president of Teamsters Local 639 who was deposed last year by union insurgents. DeBrouse also is the union leader who negotiated the beltway contract that led to the missing union dues.

Throughout his career as president of local 639, DeBrouse was associated with Excavation Construction and its president, John W. Lyon, in ways uncommon for a union leader. One of Lyon's firms built a lavish home for DeBrouse in 1973 and recently, after the federal investigation began, the firm began threatening to sue DeBrouse for money allegedly owed on the house.

When DeBrouse came up for reelection to his union post that year, Excavation Construction held a campaign party for him, providing drinks and overtime pay for union members who attended according to court records.

In 1974, DeBrouse signed a contract for his union with Excavation Construction Inc. that gave what the International Teamsters Union described as "substandard wages" for the union members.

In an internal memo obtained by The Washington Post, the International Teamsters said that the low wages were justified as a way of obtaining jobs for union members in the face of increasing competition from construction firms employing lower paid nonunion laborers.

Excavation Construction did win the $46 million contract bid to extend the Capital Beltway in Virginia. In most highway construction projects, labor makes up about three-fourths of the total cost.

The memo asserted, however, that those workers who should have been under the Teamsters' jurisdiction never did become union members because of a dispute between DeBrouse and Excavation Construction Inc. DeBrouse claimed that Excavation Construction had not provided valid forms to authorize the firm to take union dues out of the workers' paychecks. After holding the money, DeBrouse said he sent it all back to Excavation Construction to be returned to the employes, according to the memo.

Lyon has refused to comment on the entire matter. DeBrouse denied through his attorney that he has been part of any wrongdoing.

Kyle and two other former beltway workers who asked not to be identified for fear that they could lose their jobs paid their dues but were never recorded as union members. The highway payroll records, reviewed under a Freedom of Information Act request, show that the men had money deducted regularly for union dues.

However, they do not show up as members in the Local 639 records for the years they worked on the beltway. Two of the men, including Kyle, have since gone to the union to renew their membership without knowing why their names did not already show up on the union rolls. None of them has asked for a refund from the construction firm.

Until they were contacted by The Washington Post, the men did not know why their membership records were "wrong," as Kyle put it. "I went to the union when I was disabled this year. I had a toe removed and I'll be off work for about a year. The union said I'd be taken care of for my disability but they said there was some mix-up in my records."

Excavation Construction paid money into Kyle's health and pension fund administered - jointly by the company and the union during his years working for them on the beltway, making him eligible for disability pay, according to fund records. Union dues are kept in a separate account by the union.

Kyle still works for Excavation Construction, where he hopes to continue working once he has recovered. "Driving's all I've ever done," he explained. "I've got five children. I'm really on the edge now if I don't keep that job."

Another Excavation Construction driver who asked to remain anonymous said he also had gone to the union in the past year. "The lady said I had jointed recently - not four years ago. From way back I've got the (paycheck) stubs to prove I've been paying dues. She said my dues never got there (to the union). In other words, something went wrong." His dues were never refunded to him, he said.

The third worker was on the barricade crew for Excavation Construction. He said he had tried to receive union help for a grievance while he was working on the Beltway and then discovered he was not registered as a member. "I was only 19 when I got the job and I was afraid to cause trouble," the worker explained. "I didn't know why my dues were being taken out and not put in to the union and I didn't ask."

A thorough review of the missing dues was hampered because DeBrouse removed all of his records from the Teamsters local headquarters when he left office in 1977 and Excavation Construction officials have refused to return telephone calls since the investigation became public.

That happened when a subcontractor for Excavation Construction was found slain last May in a Rockville motel room. Robert Lee Miller Jr., former president of Interstate Bridge Co., was shot once in the back of his head and left dead in the motel room. Montgomery County police found $1,900 in cash on Miller and a loaded handgun in the room.

Miller had been subpoenaed by the Baltimore federal grand jury investigating how union leaders and the executives of large firms allegedly benefited while union members unknowingly lost money from their pension and health funds and failed to win well-paying union contracts.

During the court hearing for the Giant Food guilty plea, federal prosecutors said that Giant had given the unnamed union official some $11,000 worth of carpeting, the services of an architect to design a home and beach house for the official, jobs for his son, daughter and her boyfriend and season tickets for the Baltimore Colts football games. In return, the prosecutors said, the union official pledged that there would be no strikes to disrupt the delivery of produce to the chain of 115 grocery stores.

Also contributing to this story was Washington Post researcher Regina Faind.