It means that the competition in the German city is now ranked at the highest level of the IJF World Tour.

According to the IJF, the upgrade comes "after several years of good and loyal service".

More ranking points will now be available at the competition due to its Grand Slam status.

However, the 2018 edition, taking place at the ISS Dome between February 23 and 25 next year, will not be part of the Tokyo 2020 Olympic Qualification Period as that will begin in May.

Top class stars are still expected to compete with the event traditionally coming after the Paris Grand Slam in the calendar.

"We are very happy about the enhancement of our Grand Prix to being a Grand Slam," said German Judo Federation (DJB) President Peter Frese. 

"In a certain way, this can also be seen as an appreciation of the work we have been doing in the last years. 

"Now it's time for everyone of us to make sure that the first Grand Slam in Germany will be a thorough success and will make the ISS Dome in Düsseldorf rock."

The IJF will hold four Grand Slams next year, with Japanese capital Tokyo and Ekaterinburg in Russia also playing host as well as Paris.

Azerbaijan's capital Baku will not host its normal event as the city is hosting the World Championships instead.

"For us, the German Judo Federation, it is a great honour to host this competition in Germany," said DJB secretary geenral Reinhard Nimz. 

"Next year we will be a part of the Grand Slam Series and we are one of the few cities in the world which will organise this event. 

"This upgrade is a big appreciation and a compliment for our work in Düsseldorf over the last few years."