BRIDGEVILLE, DEL., FEB. 1 -- Former U.S. representative Thomas F. Johnson (D-Md.), who served a prison term in 1970 for conflict of interest, was killed today in a car accident that left his wife critically injured, police reported.

The one-car accident occurred 5.5 miles west of Bridgeville on Delaware Rte. 404 at 5:40 p.m., when Johnson's car went off the road, hit a mailbox and culvert and overturned, according to Cpl. Gerald R. Pepper Jr.

Johnson, 78, of Berlin, Md., died in a hospital in Seaford, Del., of massive injuries. His wife Agnes S. Johnson, 75, was hospitalized with multiple injuries, police said.

Johnson and his wife had been involved in a serious accident on U.S. 50 west of Salisbury, Md., in December 1985. At that time, their car hit a utility pole and ran into a ditch, leaving both in critical condition.

Johnson, who represented Maryland's Eastern Shore in Congress from 1959 to 1962, served 3 1/2 months in federal prison after being convicted of selling his influence as a congressman. His conviction grew out of an investigation of Maryland's savings and loan scandal of the early 1960s.

Johnson had been Maryland's youngest state's attorney when he was elected at the age of 24 and the Maryland's youngest state senator when he was elected in 1938 at the age of 28.

His family had been associated with Maryland for more than 200 years. His father was a former judge in the 1st Judicial Circuit Court of Maryland and brother had occupied the same bench.