Denmark’s secret service helped the US spy on European politicians including German Chancellor Angela Merkel from 2012 to 2014, Danish media report.
The Defence Intelligence Service (FE) collaborated with the US National Security Agency (NSA) to gather information, according to a report by Danish broadcaster Danmarks Radio.
Intelligence was collected on other officials from Germany, France, Sweden and Norway, according to the report.
Similar allegations emerged in 2013.
Then, secrets leaked by US whistleblower Edward Snowden alleged tapping of the German chancellor’s phone by the NSA.
When those allegations were made, the White House gave no outright denial, but said Mrs Merkel’s phone was not being bugged at the time and would not be in future.
Germany is a close ally of the US.
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 in to Danish internet cables in co-operation with the FE.
The alleged set-up, said in the report to have been codenamed “Operation Dunhammer”, allowed the NSA to obtain data using the telephone numbers of politicians as search parameters, according to Danmarks Radio.
The report follows an investigation by the broadcaster involving interviews with nine sources, all of whom were said to have had access to classified information held by the FE.
Along with Mrs Merkel, then-German Foreign Minister Frank-Walter Steinmeier and opposition leader at the time Peer Steinbruck were also reportedly targeted.
Neither Denmark’s defence ministry nor representatives for the FE have yet commented on the latest reports.
Following news of the report on Sunday, Mr Snowden accused US President Joe Biden of being “deeply involved in this scandal the first time around”. Mr Biden was US vice-president at the time when the surveillance took place.
“There should be an explicit requirement for full public disclosure not only from Denmark, but their senior partner as well,” he tweeted.
In 2013, Mr Snowden – a former contractor for the US Central Intelligence Agency (CIA) – leaked to the media details of extensive internet and phone surveillance by US intelligence.
The US then charged him with theft of government property, unauthorised communication of national defence information and wilful communication of classified communications intelligence.
Mr Snowden later sought refuge in Russia.
Prior to the evidence he exposed, top US intelligence officials had publicly insisted that the NSA had never knowingly collected data from private phone records.