Image copyright Getty Images Deutsche Telekom has confirmed up to 900,000 customers have had their broadband service cut off following a possible hack of its hardware.
That figure had now fallen to 400,000 as security measures had been implemented, the German company said.
But Reuters reported some affected customers may still be unable to make contact in order to report the problem.
Internet access, phone connections and TV reception for those with a certain router have been affected since Sunday.
“There is no error pattern: some customers are experiencing temporary problems or very marked fluctuations in quality, but there are also customers for whom the service is not working at all,” Deutsche Telekom said in a statement on its website.
“Based on the error pattern, we cannot exclude the possibility that the routers have been targeted by external parties with the result that they can no longer register on the network.”
There was no apparent geographical pattern either, Deutsche Telekom said, but there appeared to be more people affected in cities because they had a larger concentration of customers.
The company, which has 20 million customers in Germany, has issued a software update and is asking affected customers to disconnect their routers.