VIRGINIA BEACH, Va. (WVEC) -- The number of dropped drunk driving cases continues to grow following the abrupt resignation of a police officer.

About 20 DUI cases have been shelved since Officer Christopher Skinner failed to appear in court last Tuesday to testify against the people he arrested.

About 40 others are now in jeopardy, according to Macie Pridgen, spokeswoman for the Commonwealth's Attorney Office.

Skinner's sudden resignation came amid an internal investigation at the police department.

"An administrative investigation was initiated by the police department. Mr. Skinner is no longer an employee of the City of Virginia Beach," said spokeswoman MPO Tonya Borman.

Citing various Virginia Freedom of Information Act exemptions, police would not comment on the circumstances surrounding the internal review.

The 40 remaining cases, where Skinner is listed as the arresting officer, are being reviewed by the Commonwealth's Attorney office.

Prosecutors have decided not to call Skinner as a witness over questions about his credibility, Pridgen acknowledged.

Skinner had been recognized for his police work multiple times during his time at the Va. Beach Police Dept.

Mothers Against Drunk Driving awarded Skinner for making 79 DUI arrests in 2013.

He also received a life saving medal in 2012 and a special commendation in 2014, according to the city's Website.

No criminal charges have been filed against Skinner and police would not comment on whether a criminal investigation was underway.