Auditors probing the possible disappearance of up to $100,000 from the Prince George's County Sheriff's office have discovered an unexplained drop in office revenues that continued for several years.

The auditors want to subpoena personal records of certain unidentified office employes in an attempt to trace funds that they believe may be missing from county coffers, according to imformed county sources.

The auditors have found that between 1969 and 1976, the court-ordered fines collected by the sheriff's office declined dramatically when all other collections increased.

In one year, the officials said, the fine collections fell from $29,000 to about $9,000. In recent years, they have climbed again to about $37,000.

The discrepancy has led the investigators to believe that thousands of dollars in fines collected by the office may have been diverted to personal use.

Since July, the sheriff's office and county auditors have been investigating allegations that a bookkeeper in the office may have been involved in recordkeeping irregularities that led to the disapperance of as much as $100,000 in court funds over the last eight to ten years.

The target of the probe, Dolores Carobrese, committed suicide in July after her estranged husband, August M. Carobrese, made the allegations to several county officials.

The investigation has focused on the role of the sheriff's office as collection agency for the county court system. Dolores Carobrese, who worked in the office for 16 years, had controlled all fines from the time they were paid to the office until they were deposited.

To date, the investigators have identified about $1,000 in fines in a small selection of cases in 1975 and 1976 that never showed up in county accounts.

However, the abnormal drop-offs in revenue occurred before that and could indicate there were substantially greater losses.

Auditors apparently have been unable to examine the years in question because of confusing bookkeeping, missing receipts and improper entries.

In addition, investigators believe that if any money is missing it may be untraceable through county records because of Carobrese's use of a double-bookkeeping system by which fines paid to the office were recorded only on loose-leaf pages kept in her desk.

The money for the fines was left undeposited in the office safe to which Carobrese and other top aides had access, and was only entered into official record books when the court requested payment.

Investigators believe that lost receipt books and confusing entries in the books still in the sheriff's office may have been used to conceal the disappearance or misuse of public funds.

The sheriff's office has been unable to locate many records, including some personal office files, for the years covering the tenure of former Sheriff Don Edward Ansell, who left office last December.

Ansell was indicted in 1977 and later acquitted of charges that he misappropriated funds.

Since the investigation began last July, Ansell has said that all records from his years as sheriff could still be found in the sheriff's office where he left them.

However, it was learned last August that three days before Ansell left office, he personally authorized the destruction of many financial and property logs that had been used during the grand jury probe that led to his indictment.