Prince George's County Sheriff Don Edward Ansell had enough money on hand to pay his children's private school tuition in September 1976, the year the state alleges he pocketed money from a sheriff's department banquet to pay off the tuition bill, an accountant testified yesterday.

The accountant, Marlan Olson, testifying for the defense at Ansell's trial, said the sheriff had $4,968 "on hand" at the end of August 1976.

According to previous testimony, on Sept. 14, 1976, the sheriff's wife paid $2,160 in cash to the Clinton's Christian School, which the Ansell's three children attend. The state contends that part of that payment came from a sheriff's department function called the Deputy of the Year banquet, held on Sept. 10, 1976.

The 40-year-old sheriff is charged with putting to his own use $1,920 in proceeds from ticket sales for that event, then falling to report that money on his state income tax and lying to a grand jury about it.

Ansell, who has displayed a jovial manner throughout his trial, took the stand yesterday for the first time since the trial began Monday to identify the financial records he said he provided to Olson so the accountant could make his analyis.

Under questioning from Assistant State's Attorney Robert Bonsib, Ansell acknowledged that some of his financial records for the years 1974 to 1977 were incomplete or inaccurate.

Ansell said that on his 1975 income tax return he had declared $4,712 as income from a sheriff's department testimonial dinner held in his honor that year, but last week he was advised by Olson that his financial records show he actually made about $5,700 on the dinner.

Victor Hulon, Ansell's attorney, said it was "pure accident" that Ansell made an error in computing his income from the 1975 testimonial dinner.

The documents the sheriff provided the accountant also did not include most of the records relating to a trip to Disney World that Ansell and his family took with Enid Smith, one of his top assistants, and her family the day after the testimonial dinner was held, the sheriff testified. Smith was one of the chief organizers of the June 1975 dinner.

Olson maintained, however, that there was only about a 5 percent chance of error in the analysis he made of the sheriff's finances.