"Unfortunately we first learned of the Bundeswehr's statements about the G36 rifle through press questions," the company said in a statement.
They maintain that the G36 is a "globally recognized, technologically leading assault rifle" and that "the results currently being published contradict totally the comprehensive and laborious testing that Heckler and Koch conducted itself in light of the rumours".
"Heckler & Koch does not recognize the negative results supplied by the Bundeswehr on the G36 rifle".
Defence Minister Ursula von der Leyen had admitted on Monday that the German army's standard rifle suffered from an “accuracy problem” – almost 20 years after it was first brought into service.
'“The G36 apparently has an accuracy problem in high temperatures and also when it's overheated from firing,” von der Leyen said.
She added that following a report from Bundeswehr chief of staff Volker Wieker the army will limit use of the weapon.
Reuters reported that in the long term, soldiers may have to be equipped with a different rifle.
The Bundeswehr has bought 176,000 G36 rifles from Heckler & Koch since 1996.
It has also been exported to dozens of other countries for use by soldiers, police and special forces all over the world.
Several thousand were recently sent to Kurdish Peshmerga fighters in Iraq for the struggle against Isis.
In July last year an internal Bundeswehr report criticised accuracy problems with the G36, and the Süddeutsche Zeitung reported in November that the Defence Ministry tried to water down the report.
Von der Leyen assembled a committee of military and civilian experts in mid-2014 to look into the weapons.
Although it has yet to report, von der Leyen has previously said that its conclusions “tend in a definite direction”.
Defence expert Tobias Lindner of the opposition Green party said that the problems show "that in the Bundeswehr there are massive problems with the simplest kinds of basic equipment".