The only confirmed documentation of a German made poison bullet from WWII that I know of was the material put together for the IAA Seminar at SLICS some years ago and later published in the Journal (#451) which included a photograph of the 7.65mm poison bullet cartridge.
The development and use of these cartridges was covered in the proceedings of the Nuremburg Trials. The work began after the Germans acquired some Soviet made 7.65 Browning poison bullet rounds. The initial work was with 9x19mm and 45ACP loads, but it was determined that these would generally pass through the target and that it was appropriate that the bullet remain in the victim so that more poison remained in the victim. The poison used by both the Soviets and the Germans was reportedly aconite. Five condemned Soviet POWs were shot in the leg with German 7.65mm poison bullets. In two cases the bullet exited the leg and no effect of the poison was noted. In the three cases where the bullet remained in the leg, the victim died within a few hours. This activity was going on in mid-1944.
Reportedly 200 of these 7.65mm rounds were delivered to Skorzeny’s Jagdkommandos supply organization. Skorzeny claimed he received 40 rounds in the Spring of 1944. In addition the Reichkiminalpolizeiamt received 40rds, and possibly additional ammunition (30rds) were delivered to the Jagdkommandos.
Given the unsuitability of the 9x19mm and 45ACP for use with a poison bullet because of excess penetration, the utility of a 7.9mm poison bullet seems very questionable.
I would be very interested in any source information on the 7.9mm poison bullet, or on a 9x19mm poison bullet made by the Germans. Lots of speculation on this area but except the the article cited, I have seen little confirmation.