KIEV - Around 20 men are crammed into the foul-smelling cell, where cockroaches wander across the walls and barred windows.

This is one of Ukraine's most notorious prisons, the Lukyanivska facility in central Kiev, where improvements have long been promised but have yet to materialize.

"This is how it is," said a prisoner as he pulled back a piece of fabric that barely separates a toilet - covered in a thick layer of mold - from the rest of the room.

Largely unchanged since the Soviet period, the Ukrainian penitentiary system is infamous for its dire conditions.

Pro-Western Ukrainian authorities launched efforts to reform the creaking infrastructure two years ago, but the project has stalled largely because of a lack of funding.

"A prison is not a cognac, it does not improve with age," deputy justice minister Denys Chernyshov said of Lukyanivska, which has a 150-year history.

'NO POINT IN A MAKEOVER'

Over the years it has been home to numerous high profile prisoners, including the future leader of the Soviet secret police Felix Dzerzhinsky, the filmmaker Sergei Paradzhanov and many dissidents.

More recently former Ukrainian Prime Minister Yulia Tymoshenko was also held in the women's wing, where conditions are slightly better.

Some of the buildings in the prison complex have been renovated but the only way to improve the rest is to knock them down, said Chernyshov.

"The way things are at the moment it is impossible to get rid of the mold because it has gone all the way through the walls - there is no point in trying to do a makeover," he said.

"It is necessary to build a new building."

With 2,500 inmates, Lukyanivska is among the worst of its kind, according to a report made this year by the Ukraine's Ombudsman.

Kiev authorities have put the land on the market, with a view to using the funds to construct a new facility outside the capital.

But Chernyshov admits they have not yet received an offer.

TAKING TURNS TO SLEEP

Andriy Didenko, who spent eight years in Ukrainian prisons before he became the coordinator of a human rights NGO, said things are slowly improving from an extremely low base.

In the recent past, "in cells that were designed for four people, you might see 10 or 12 prisoners. Some people did not even have a bed and had to take their turn to sleep," he said.

He said the situation in detention centers - where people are kept before and during their trial, in a process than can take years - is getting better, because of a new law that allows some to stay under house arrest that prevents overcrowding.

Of 57,000 people currently incarcerated in some 140 Ukrainian prisons, a third are in detention centers, according to official figures.

But rights groups and foreign governments paint a gloomier picture of conditions than Didenko.

The Ukrainian Helsinki Group, a human rights watchdog, has said life imprisonment in the country was comparable to a "slow execution" because of "nightmarish detention conditions".

Ukraine's Ombudsman, which over the last year alone recorded 1,500 complaints by prisoners, said "no significant improvement... has taken place".

Chernyshov says financing is the major problem stopping reform, but even if adequate funding was granted tomorrow it would take years for improvements to be seen.

"This is a long process," he said.