"He never touched a weapon, never joined in any demonstrations," his father, Edward Six, told The Associated Press. "He just was on the street. He talked to all these normal people. He asked them questions and put that on the internet."
Authorities have yet to comment on the arrest, which took place three weeks ago, leaving Six's family grasping for answers and German diplomats in the dark. So far they have been unable to visit the 31-year-old in the infamous Helicoide prison in Caracas where he is being held alongside some of the government's most strident opponents.
The case has alarmed press freedom groups. While Maduro's government has little tolerance for critical coverage by local press, foreign journalists who cross officials are usually spared the same harsh treatment. In the past, foreign reporters, like Six, who weren't accredited would stay in custody for just a few days before being ejected from the country.
Six's father said officers first noticed his son on Nov. 16 during the search of a nightclub in the Caribbean oil town of Punto Fijo. Six didn't have his passport on hand, so officers escorted him to his hotel for questioning, according to his father, who declined to say how he knows details of his son's plight.
The next day, a team of 15 officers — two in civilian clothes and others heavily armed in special forces gear — scooped him up from his hotel. He was later charged with espionage, rebellion and violating a security zone and has remained in isolation, according to his father, adding that his son has not been harmed.
Six's father believes officials are using a photo his son took of Maduro at a May rally in Caracas as evidence in the case. But Edward Six said the photo was taken from behind a security perimeter far away from the leader.
The Venezuelan information ministry did not respond to a request for comment. In Berlin, the German Foreign Ministry said Friday it cannot give any details about the case, citing privacy laws. A German diplomat said Venezuelan officials have not allowed diplomats to visit Six, a right guaranteed by international law. The diplomat was not authorized to discuss the case publicly and agreed to speak only if not quoted by name.
"Three weeks after his reported arrest, there have been no updates about his conditions or the charges against him," the New York-based Committee to Protect Journalists said in a statement. "This poses a serious threat to the country's already limited press freedom."
Resident of a Berlin suburb, Six has travelled the globe as an independent journalist for 12 years, publishing his reports in right-wing outlets. His recent arrest has generated little interest in mainstream German media, which relatives blame on his conservative affiliation.
This isn't Six's first arrest amid turmoil. In 2013, he was jailed by the government of Syrian President Bashar al-Assad for three months after illegally entering that country to report on its bloody civil war. Talking to reporters after his release, Six described hearing the screams of people being tortured at night, but he was eventually handed over unharmed to Russian diplomats in Damascus who had helped secure his release.
A photo posted on Six's Facebook page in May 2011 shows him holding a rocket-propelled grenade launcher on his shoulder, with a caption indicating it was taken on the front line of fighting in Syria. Six turned his attention to Venezuela over a year ago. His father said he entered the country legally but was unable to secure journalist credentials required by Venezuela to work as a reporter.
Ronald Glaeser, a friend and editor at the German weekly Junge Freiheit (Young Freedom), said Six "is going into places and situations that most journalists wouldn't try to go ... He puts himself in danger — unfortunately too often."
While reporting on Venezuela, Six posted two crudely edited German-language videos online showing him walking the streets, interviewing people and at times narrating his conclusions, critical of Maduro's socialist government.
"Hola amigos, I'm still in Venezuela, South American socialism of the 21st century," Six says, opening one video. "Here on the street there's dust, dirt, garbage, street dogs."
Associated Press writer David Rising in Berlin contributed to this report.