A former Danish defence minister, Claus Hjort Frederiksen, said on Friday that he had been charged under a law that deals with divulging state secrets.
He did not say what he was accused of leaking, but insisted he would never do anything to harm Denmark.
On Monday, it emerged a former foreign intelligence chief was being held on the same charges.
Lars Findsen, has been in prison for a month, also for allegedly leaking top-secret information.
He described the charges as “insane” and said he would be pleading not guilty.
Mr Frederiksen said he had spoken out on a political issue, but did not say which one. He was defence minister for three years to 2019 as well as chairman of the Intelligence Services Committee.
There has been no comment from prosecutors but Danish media say the ex-minister had previously appeared to confirm the existence of a top-secret collaboration with the US, which allowed Washington to use Danish data for spying.
