Hertha Berlin have a mole in their camp, literally, and it is causing havoc with training head of their first Bundesliga game of the new season on Saturday.

Molehills and burrowing lines keep appearing on Hertha's training pitches.

Hertha coach Pal Dardai suspects a family of moles are digging under the training complex at the Olympic Stadium, and that has hit preparations for Saturday's home against Nuremberg on the opening weekend of the new Bundesliga season.

Luckily, the moles have only targeted the training complex and the playing surface at the nearby Olympic Stadium is unaffected.

"I have never seen such a big hole. That must be several moles, so many holes can't be dug by just one," an exasperated Dardai told German daily Bild.

The Hungarian is a keen gardener and is baffled by the number of molehills and holes which keep appearing.

"Maybe they are Hertha members and just want to watch us practice," he quipped.

"Joking aside, we can't train on all parts of the pitch right now, that's too dangerous, because there is a risk of injury especially to ankles."

As a result, Hertha have switched their sessions to another part of the training complex and a team of experts have been tasked with removing the moles.

However, the critters will have to be gently evicted.

In Germany, Moles are a protected species with a fine of up to 50,000 euros ($57,773) if killed or injured.