Torpedo-bomber version of Do 217M. Only a single prototype was built, the Junkers Ju 88 being chosen as a torpedo-bomber instead. The M-5 series was a modified version of M-1 fitted with Hs 293 missile recessed under fuselage. Only one prototype was built.

The last in the M series was the M-11. It was a revised anti-shipping version of M-1, with extended wings of K-2 and provision for one Fritz-X or Hs-293 under fuselage. 37 M-11 were converted from M-1 airframes.

Sources:
Gunston, Bill - The Encyclodepia of the Worlds Combat aircraft, 1976, Chartwell Books, Inc., New York
Brown, Eric, Captain - Wings of the Luftwaffe, 1979, Airlife Publishing Ltd., Shrewsbury
Gunston, Bill & Wood, Tony - Hitler's Luftwaffe, 1977, Salamander Books Ltd., London
Donald, David - The Complete Encyclopedia Of World Aircraft, 1997, Brown Packaging Books Ltd., London
Wikipedia - Dornier Do 217