New details suggest that Harvard Police Lt. Lawrence J. Murphy is all but a partner in the bus company whose work he arranges and oversees for the University's Commencement and reunion activities.

The company, Cavalier Coach Corporation of Medford, Mass., has received the transportation contract for Commencement and the reunions for the last six years. There is no competitive bidding for the Harvard contract, which is worth an estimated $125,000 a year to Cavalier.

Murphy, who says he decides what bus companies to employ for reunions, has repeatedly understated the extent of his role in Cavalier. In an interview last May, Murphy said he had no financial or personal ties to the company.

But later in the year, Murphy was forced to acknowledge that he is involved with the financial maintenance of Cavalier. The lieutenant is authorized to sign paychecks for company employees, and he holds an American Express Corporate Card in Cavalier's name.

In addition, Murphy acknowledged being a close personal friend of Cavalier' owner, Joan Libby. The two have vacationed together in Florida, and The Crimson observed Murphy entering Libby's home on two consecutive evenings last fall. Murphy said he visited Libby to console her following the death of her mother.

In making these admissions, Mur- phy said he was acting as little more than afriend of the company. He said he only had thecredit card and check-signing power in caseanything happened to Libby.

But in interviews over the past month, Cavalieremployees, owners of other bus companies andentrepreneurs who have hired the company have saidMurphy is involved with nearly everything Cavalierdoes.

Murphy, sources say, shows up at the Cavalieroffice throughout the year, and his work is notlimited to helping in the planning of Harvardactivities, as the lieutenant insists. Heorganizes bus schedules, meets with clients andreceives mail at the company's Medford office. Histwo children have even done work for the companyaccording to a source.

Murphy has also traveled on behalf of thecompany, twice attending the annual United BusOwners of America convention with Libby. Murphysaid in January that he would have joined Libbyfor this year's convention in San Antonio, but hewas ill.

Libby, in a phone interview last week, saidMurphy has never had any relationship with hercompany.

"Lt. Murphy has absolutely nothing to do withCavalier," Libby said.

She said the matter had been investigated byauthorities, but declined to comment further.

Harvard officials maintain there is nothingwrong with Murphy's ties to Cavalier because thebus company has provided excellent service. VicePresident and General Counsel Margaret H. Marshallhas said that the arrangement does not violateHarvard's policy on conflicts of interest.

"There are many reasons why institutions orparts of the institution use vendors on a repeatedbasis," Marshall said last fall. "Excellence ofservice is one. Price is another. Reliability is aa third."

Murphy declined to comment last week. "I'veanswered all those questions for you," he said."and I don't think we have to go back into thatagain."

But it's not hard to find examples ofMurphy's close ties to the company. Take, forexample, his involvement with one contract thathas absolutely nothing to do with Harvard.