A few weeks ago, one of the largest architectural firms in this northeastern Maryland community had a $500,000 contract canceled after newspapers reported that its records had been subpoenaed by federal prosecutors. The client felt we were too hot to handle," said John Lininger board chairman of the firm.

Worried bankers also called and questioned the integrity of the firm's officers after the subpoenas were publicized.

The symptoms are by now familiar in Maryland: another federal investigation of corruption was under way - the sort that produced the recent conviction of Maryland Gov. Marvin Mandel.

Hartford County - a patchwork of rolling diary farms and small towns and developments where all this is taking place - is a relatively closely knit community and everything is felt more personally.

Hartford County Executive Charles B. Anderson Jr., whose personal financial records have also been subpoenaed, recalled that when he used to stroll down Main Street in the county seat here people used to greet him and start up a conversation. "Now, they seem reluctant," he said.

Five weeks ago, prosecutors subpoenaed Anderson's personal financial records and thousands of county contracts negotiated during his nearly five years in office. Investigators also subpoenaed the records of business owned by Anderson's friends and political supporters, including the Belair architectural firm.

Once news of the subpoenae broke this small county seat began swimming in speculation. It quickly became the popular view that federal prosecutors able to obtain the convictions of shrewd Maryland Gov. Marvin Mandel and the executives of two nearby counties would have little difficulty here. (In fact, the same corruption team is not involved in this investigation.)

"Those guys in Baltimore have some pretty big scalps on their belt," one high-ranking county official said. "The feedback I'm getting is that Harford County is next."

Even though the grand jury has just begun collecting data and the investigation has not produced a single charge, those named in the subpoenas have found themselves anguishing over past decisions, worrying about heavy legal fees and becoming defensive with old friends and business associates.

"It's a terrible feeling," Anderson said in a interview last week. "I can probably relate it to when my father died. You couldn't go for a while later without thinking about it. It's the same thing with this. Everything comes back to the investigation."

The most dramatic incident since news of the investigation broke was the suicide Sept. 4 of George E. Campbell, a 44-year-old lawyer-real estate investor and Anderson ally, whose records were among those subpoenaed a few days earlier.

Campbell was distressed by the subpoenas, the adverse publicity and the persistent questions of reporters, according to his friends and family. Police said he shot himself in the head in a Belair office building that was named after him.

The suicide fueled speculation about the investigation. According to a courthose figure here, "People began realizing fast that (the prosecutors) aren't going after things minor."

Within the Anderson administration, morale sank so low that the executive had to cut short a long-planned, cross-country motor trip to return home and bolster sagging spirits of his department heads who felt their own integrity was under question.

"Obviously, when there's an investigation in your county, it's discouraging," said Richard Rex, the Harford parks director. "It's sort of a questioning period. There's a little bit of second-guessing."

Even Anderson, a blunt-talking, boyish-looking Democrat, who first pooh-poohed the investigation as a "fishing expedition," expressed apprehension about the probe and conceded he too has been wringing hands over past decisions.

"You think about people you helped and think, Damn, I wonder what the background was on that," he said. "You can always turn up something that isn't 100 per cent right. If they do, it's because I helped somebody I felt so sorry for. I never received one blessed cent from anybody to do something."

Anderson's county of 140,000 people, nestled between the Pennsylvania line and the Susquehanna River, is not a tranquil place politically in the best of times.

Almost as soon as he took office in January, 1973, as the first Harford executive under charter government, Anderson and a conservation-minded County Council have fought bitterly over development rights in a county lacking adequate facilities. Council members have accused him of showing favoritism in awarding consultant contracts. There have been investigations started by Anderson and the Council and a local grand jury recently indicated a local developer on charges of bribing the county's zoning administrator.

Harford County's march toward development, according to some local observers, has created a climate here similar to the one that existed in Baltimore County of the 1960s, where, federal prosecutors discovered later, county officials took cash kickbacks in exchange for nonbid county contracts.

"You've got a lot of people wanting to get here and a lot of people trying to keep them out," a high-ranking county official said. "Because you've got a lot of money hanging on that, the circumstances are ripe for this (investigation) to happen."

Harford County's ever-day political intrigue quickly took a back seat once federal prosecutors blanketed it with subpoenas, following the same pattern that they used in the investigation of Baltimore county that eventually led to the conviction of former executives Dale Anderson (who is no relation to Charles Anderson) and Spiro T. Agnew, who had become Vice President.

For the businessmen whose records were subpoenaed, life has become an endless series of questions from friends and the press. In interviews, they express resentment towards the prosecutors and aprehension about the impact of publicity on their reputiations.

"They throw out a sinking net and if they don't catch you, it still costs you money and hurts your integrity," said Lininger, of the architectural firm of Tater Lininger Clark Wood.

"There ought to be some sense of responsibility."

Banks that lend his firm money, he said, have called and asked "if we're going to come out of this clean. They don't like a client who owes them 50,000 to appear in the paper like that.

"I'm in the architect business and our business relies on reputation," he said. "It's a business of integrity. When your name appears in the paper with allegations, it hurts us very much. It's a monetary loss."

Lininger said his friends call him with the apparent motive "of getting me to say something. I just stay away from the country club because I can't talk about just nothing. My wife's getting a little bit nervous about it. Her friends drop little remarks."

The prosecutors in Baltimore have a reputation for ruthlessness, Lininger said, a fact that makes him "a bit apprehensive." What really worries him however, is the possibility of getting drawn into a criminal investigation through circumstantial evidence or the testimony of a scared witness who trades bogus information for immunity.

"You may get nailed even though you din't do something," he said. "I used to think that if you were innocent, you have nothing to worry about but I'm not so sure about that now."