Delays in the retrial of men accused of beating a black American graduate to death in Greece has thrown a spotlight on the country's snail-paced justice system.

Texan Bakari Henderson, 22, was set upon by a group of mostly Serbian men on the holiday island of Zakynthos in 2017 in a horrific attack captured on video.

With the White House now pressuring Athens for action, insiders say the case is typical of the chronic dysfunction of Greece's legal system.

"In no other country in Europe are procedures so time-consuming, so complicated and so repetitive," Supreme Court prosecutor Vassilis Pliotas told AFP.

When US Vice President Kamala Harris met Greek Prime Minister Kyriakos Mitsotakis in February, she reportedly quizzed him about the delays in the Henderson case.

In an angry statement days later, Greek judges said it was "unfair" to blame them, warning officials to stay out of judicial business.

The Henderson case has made little progress in four years after a retrial was ordered when prosecutors deemed his attackers had got off too lightly.

Of the nine tried, three walked free and six were sentenced to between five and 15 years in prison for assault rather than murder. Only one is still in jail.

Covid-19 has badly disrupted Greek courts, but even before the pandemic, trials were habitually postponed, frequently because lawyers were busy elsewhere and requested adjournments.

A 2016 strike by lawyers over planned changes to their pension fund also paralysed the system for nine months.

Foot-dragging by judges is another key problem, said veteran justice reporter Panagiotis Tsimboukis, who called the delays a "denial of justice of pandemic proportions".

More than 40 laws have been passed over the years to speed up judicial procedures, and over a dozen judges were fired in recent months for excessive delays, Tsimboukis told AFP.

But the problem persists.

Vassilis Chirdaris, a Supreme Court lawyer with extensive experience at the European Court of Human Rights (ECHR), said "nobody obeys" a requirement to resolve trials within three years.

Some cases have been stuck for 14 years in Greece's top administrative court, the Council of State, and over 4,000 hearings have been postponed at least once, Tsimboukis said.

Some cases have been stuck for 14 years in Greece's top administrative court, the Council of State
Some cases have been stuck for 14 years in Greece's top administrative court, the Council of State AFP / LOUISA GOULIAMAKI

"The volume of cases overwhelms judges" who then try to offload the burden to colleagues, he claimed.

The Athens prosecutor's office alone can amass 450,000 lawsuits over a three-year period, Pliotas said. "That's around a million people involved."

The ECHR has repeatedly fined Greece for excessive case delays, penalising the country more than 500 times since 1959, according to Chirdaris.

Outdated facilities and short court hours don't help, he argued.

Case files are wheeled about in supermarket trolleys at the Athens court complex. The former military academy was last refitted nearly four decades ago.

One of the buildings has no elevator, so documents are hoisted upstairs with a winch.

In the building that houses first instance rulings, court documents headed for the archive room are lined in knee-high stacks on the floor.

The bulging folders snake up the stairs to the first floor and into the ladies' and men's toilets, tucked under sinks and blocking two cubicles.

"Conditions here are tragic," said Yiorgos Diamantis, head of the federation of Greek legal operatives.

Not only are the buildings archaic and the courtrooms too small, but the federation says it is short of 3,000 staff, with 1,700 more reaching retirement age.

Steps have been taken in recent years to increase online access to cases and rulings, and the pandemic gave the process further impetus.

The justice ministry is also working on a bill setting out new limits on case postponements.

But a significant part of the system remains stubbornly old-school.

"Older judges and lawyers are uncomfortable with going digital. At the Athens appeals court, four in 10 rulings are still written out by hand," said staff federation spokesman Sotiris Tripolitsiotis.