The cancer affects just a few in every 100,000 people but the study comes on top of many other conflicting claims about the dangers of mobile phones.
A report commissioned by the British Government last year said that, despite the widespread fears, no conclusive links with cancer had been proven.
Conversely, because there was also no proof that the phones were safe, it recommended that use by children, at least, should be limited.
The German study, to be published this month in the journal Epidemiology, follows research among 118 patients with the eye cancer.
Dr Andreas Stang of the University of Essen, who led the team, cautioned that it needed confirmation.
The researchers were unable to measure how much radiation the study volunteers had been exposed to, limiting the significance that could be placed on the findings.
Critics claimed this meant the data was fundamentally flawed. Neverthless, it will still cause concern within the mobile phone industry which is currently facing multi-billion dollar lawsuits from customers in the U.S. who claim they have contracted brain tumours.
However, a new American study has found no evidence that the phones can trigger such tumours.
Experts who questioned almost 500 people with brain cancers discovered they had not used mobiles any more frequently than a similar number who had remained healthy.
But they admitted the study could not answer the question of whether there is any risk from long-term use.
The scientists said further research was required as they were looking at people who has mostly used mobile phones for a relatively short period of time – two to three years.
Dr Joshua Muscat, an epidemiologist at the American Health Foundation, who led the study, said: ‘The data showed no correlation between the use of cellphones and the development of brain cancer. In addition, there was no association between the amount of cellphone usage and brain cancer.’
New Department of Health leaflets advise potential phone buyers to consider the SAR rate – the rate at which radiation is absorbed into the body – when making their choice.
Children under 16 should be ‘strongly’ discouraged from using mobiles for non-essential calls and everyone should keep calls as short as possible.
Youngsters are thought to be particularly at risk from any potential health hazards because they have thinner skulls and their immune system is still developing.