Prisons in most German states are operating at capacity, if not exceeding it, according to a survey published on Wednesday by Essen-based publisher Funke Media Group.

In Baden-Württemberg, occupant capacity exceeded 101.3 percent for male prisoners last year, while in Rhineland-Palatinate, it jumped from 99.99 to 100.6 percent in January. Prisons in other states, including Bavaria, Berlin, Hamburg and North Rhine-Westphalia, surpassed 90 percent of occupant capacity.

Read more: Amid controversy, Germany's police struggle to find recruits

According to experts cited in the report, actual capacity tends to be 85 to 90 percent of official capacity since parts of a prison may be closed or undergoing renovation.

'Right to be concerned'

Researchers have warned against exceeding capacity at prisons, saying it jeopardizes the safety of staff and undermines the prospect and success of inmates' re-entry into society.

Catherine Heard, director of the World Prison Research Program at University of London's Institute for Criminal Policy Research, told DW that German authorities are "right to be concerned about prisoner numbers exceeding official capacity."

"Stretched resources compromise [a] prison's ability to achieve its main goals — preparing prisoners for a return to the community and equipping them with the skills and support necessary to avoid further crime and play a full part in society," Heard said.

"Research shows that overcrowded, under-resourced prisons offer fewer rehabilitation and education programs, less time outside the cell and greater use of solitary confinement."

Nothing new

But overcrowding in German prisons isn't a new phenomenon. Data show that in 2006, Germany's prisons were at their limit — if not exceeding it — with occupancy rates falling between 95 percent and 105 percent of official capacity.

Even before that, overcrowding was an issue. In the 1980s, Germany experienced overcrowded prisons "as a consequence of sentence enhancements in drug laws and a corresponding wave of long prison sentences," according to Hans-Jörg Albrecht, director at the Max Planck Institute for Foreign and International Criminal Law in Freiburg.

Read more: Police in Germany kill more than you think

"Changes in the structure of prison populations, which started to take effect in the 1980s, point to the over-reliance on imprisonment as a response to developing and expanding drug markets," Albrecht said in a report.

Researchers fear that similar disciplinary measures could see resurgence. Last year, while Germany witnessed one of its largest year-on-year decreases in crime, drug offenses rose 9.2 percent, comprising 330,580 cases.

Expanding capacity

Several German states have signaled their intention to expand capacity in order to meet the demands of the criminal justice system.

In North-Rhine Westphalia (NRW), the state government is planning to increase the number of places for inmates from its current number of 18,925, of which only 17,559 are available.

"In the coming years, the state government will invest nearly €1 billion ($1.22 billion) into constructing and renovating correctional facilities. That's already decided," Peter Marchlewski, NRW Interior Ministry spokesman, told DW.

Read more: Are refugees more criminal than the average German citizen?

However, Marchlewski noted that prisons in the state are currently operating at more than 90 percent of official capacity, exceeding what researchers consider actual capacity. "Of the 17,557 detention places available today, 16,388 are occupied. That leaves almost 1,200 places available," he said.

"In addition, under the current budget, NRW Interior Minister Peter Biesenbach has allocated 1,135 jobs for the judiciary in 2018 alone," Marchlewski added. "This naturally benefits the prison system."

While boosting operational capacity may ease the administrative burden on the prison system, is expanding space to hold more prisoners the right approach to overcrowding? Researchers believe there are alternatives.

A new way forward

From developing more opportunities for parole to diverting minor cases out of the criminal justice system, experts have pointed to several alternatives to pre-empt, prevent and ease overcrowding in prisons.

"One easy way to take some of the strain off prisoner numbers is for Germany to stop imprisoning people who are too poor to pay their day-fine penalties," Heard said.

"Recent research has shown that around 8 percent of Germany's prison population today is made up of fine defaulters and the most common offense they were fined for is riding public transport without a ticket," she explained. "In this day and age, it's surely not right to punish poverty in this way."

Read more: German states look to reintegration to reduce migrant crime

Whether there is political will to explore these alternatives remains to be seen. But German lawmakers have called for the issue to be addressed.

"The penal system must not be neglected," Volker Kauder, who leads the ruling conservative Christian Democratic Union (CDU) parliamentary party, told Funke Media Group. "The conditions in German prisons must be improved."