Video report by ITV News Senior International Correspondent John Irvine
"I realised why the regime use detention against its people - because it is very effective," journalist and activist Wafa Mustafa tells ITV News.
"By detaining someone, you do not only silence and disappear them, but you also break their loved ones, their families, their communities."
In March 2011, Syrians inspired by the Arab Spring began demonstrations against President Bashar al-Assad's regime. Assad's government cracked down on the protests using deadly force and as a result, a bitter civil war erupted. ITV News has been marking a decade of the Syrian war, in which hundreds of thousands have died and millions have been displaced. Additionally, almost 150,000 Syrians are still detained or missing.
Source: Syrian Network for Human Rights
Wafa Mustafa's father is one of the many who disappeared. Ali Mustafa was arrested almost eight years ago by the Syrian regime and hasn't been seen since.
Wafa describes her dad as "hard-working", "smart" and "open-hearted".
"He raised us, my sisters and myself, to actually be political, to ask questions, to always get involved, and to work very hard for our communities," she adds.
A neighbour of Ali's claims that in July 2013, a group of armed men broke into his house when the rest of the family was out. Wafa believes her dad's best friend, Hassam Al-Dhafri, was also abducted.
The following week, Wafa, her mother and sister fled the country.
"In Syria, when the regime arrests someone, especially men, they usually arrest other family members, especially women, to pressure the detainees to admit that they've done things no one knows about," she says.
The trio embarked on a "difficult" journey to Turkey ("we had no money, no relatives, nothing"). Wafa eventually moved to Berlin in order to study. Since graduating last year, she's been advocating for missing Syrians and continuing to search for her father.
"Since the day of my dad's disappearance, we've been trying every possible way to get information about him," Wafa says.
"I mean, Syrians have now tried millions of ways to learn about the fates of their loved ones."
In a bid to track Ali down, the family has hired multiple lawyers and sought information from both acquaintances and "connections of connections". They've exhausted several options, including paying money to the regime in exchange for Ali's whereabouts.
Wafa believes freedom for Syria is possible
"Unfortunately, the regime doesn't admit that they have him," Wafa says.
As part of her fight for justice, Wafa has addressed the UN General Assembly and the UN Security Council.
However, she is best known for her protests outside a German courthouse where a former senior Syrian military official is on trial for alleged state-sponsored torture and murder.
Alongside other Syrians, she sets up camp outside the building, armed with large, framed photos of missing Syrians.
Several passers-by stop to enquire about the imposing faces.
Wafa explains: "When we told the stories, people were shocked. It was shocking for me also that people didn't know, Almost everyone said 'we know there is a war in Syria, but we don't know about this'".She believes this ignorance is partly down to misinformation spread by the Syrian regime and Russia (Assad's ally)."Our lives are denied, our truth is denied," she says.
When asks what what she'd like to tell the international community, she firmly responds: "Any solution for Syria that does not start with the release of all detainees, with the prosecution of all the war criminals in Syria, starting with Assad and his inner circle, will not be sustainable."
Despite Assad waging war on his own people for a decade, Wafa believes her goals for Syria are not naive.
Wafa says detaining people "breaks their loved ones, their families, their communities"
She says: "Freedom has proven to be slow and difficult, but it's not impossible.
"I believe there are still people inside Syria and outside Syria who still believe change can happen."
Whenever Wafa feels pessimistic about the state of her homeland, she thinks of her father, who "would've said that [freedom] is not impossible".
Human rights organisation The Syria Campaign has released an animated video imagining what would Syria have been like if Assad had stepped down 10 years ago.
Still, she sometimes questions how she endured a gruelling eight years without her father.
"How am I still surviving the past eight years? How am I surviving every day?," she asks.
"I really don't know, But I know that till I die, I will never give up seeking the truth of my father's fate."