The home telephones of Maryland Attorney General Francis (Bill) Burch were "tampered with" last week according to Baltimore police investigators. They have not yet, however, determined why.

Burch, a candidate in this fall's gubernatorial primary, asked for a police investigation after a telephone repairman discovered that wires leading from Burch's phones were cut as they reached the top of an outside telephone pole.

"Somebody tampered with those phones," said Lt. Joseph P. Newman, the police investigator. "You can speculate whether it was a burglar or someone tapping his phone. We don't have all the answers yet."

Burch, who lives in an affluent north Baltimore neighborhood, said the possibility of an illegal wiretap "disturbs me greatly." He said he has had state police sweep his home and office for electronic devices.

"Whether somebody wanted to hear me talking about a grand jury investigation with my staff or a political opponent wanted to know what I'm doing, I just don't know," he said. "It's a mystery to me."

Burch said he first suspected something was wrong on July 4 when his son found the home phones dead. A repairman, responding to the complaint, climbed the telephone pole in a secluded area behind the house and discovered the cut wires.

Lt. Newman said he has eliminated every possible cause for the severed wires except burglary and wiretapping. But, he said, there are mitigating factors that make it difficult to pinpoint the motive.

The wiretapping theory seems plausible, he said, but electronics experts know of no way to tap a phone by cutting the line. Most taps are placed on a line by simply attaching a new wire to intercept the current.

Nevertheless, he said, he has not ruled out the possibility of an "incompetent wiretapper" who mistakenly cut the line while trying to tap it. It is also possible that a tapper severed the wires after removing a tap, he added.

A house burglar may have cut the line in an attempt to shut down the burglar alarm system in the attorney general's home, Newman said, although there was no evidence of forced entry or burglary of the residence.

The lines were cut less than an inch from a terminal box attached to the top of the 15-foot pole. The box services three homes, but only the attorney general's phone wires were cut.

Newman said he has not been able to inspect the severed portion of the wire to determine if it had been attached to a wire tapping device. The repairman discarded that section after reconnecting the line, he said.

"All we know is we have a tampering," Newman said. "Whether it was a wire taping or a burglary, we don't