Denmark's secret service collaborated with the US National Security Agency (NSA) to help the US spy on European politicians including German Chancellor Angela Merkel from 2012 to 2014.

Reports in the Danish media claims that intelligence was collected from The Defence Intelligence Service (FE) on other officials from Germany, France, Sweden and Norway.

In a new report shared with several European news agencies, the NSA is said to have accessed text messages and the phone conversations of a number of prominent individuals by tapping into Danish internet cables in cooperation with the FE.

It is the second time such allegations have surfaced, with similar allegations made in 2013 following leaks from Edward Snowden. 

A report, seen by media outlets on the continent, "Operation Dunhammer", allowed the NSA to obtain data using the telephone numbers of politicians as search parameters.

In Germany, it is thought that Angela Merkel,  then-German Foreign Minister Frank-Walter Steinmeier and opposition leader at the time Peer Steinbruck were targetted. 

Denmark's Defence Minister Trine Bramsen, who had reportedly been earlier informed of the espionage, told Danmarks Radio that "systematic wiretapping of close allies is unacceptable".

After the news surfaced, Snowden, a former contractor for the US Central Intelligence Agency, tweeted: "Biden is well-prepared to answer for this when he soon visits Europe since, of course, he was deeply involved in this scandal the first time around. There should be an explicit requirement for full public disclosure not only from Denmark, but their senior partner as well."