Torture in Jordan is practised "with impunity" and there is no guarantee Abu Qatada will get a fair trial, a senior researcher at Human Rights Watch has told the Huffington Post UK.
Christoph Wilcke said changes to the Jordanian constitution, which have made gathering evidence by torture illegal, are not being enforced.
Home secretary Theresa May's legal case for deporting Abu Qatada rests upon assurances from Jordan that evidence received through torture could not be used in a Jordanian court of law.
However Wilcke, a specialist for HRW's Middle East and North Africa division, pointed to a clause in the new constitution, introduced in 2011, that gave courts a three-year grace period to apply the changes.
"We just really don't know if it is being enforced," he said.
"Civilians are still being tried in the state security court, another amendment that was changed in the constitution, so it seems they are making use of the three-year period."
He added Jordan "continues to have a torture problem," and described some of the brutal methods used to extract so-called confessions.
"Most commonly prisoners are subjected to falaka or 'ghosting'" he said.
Falaka is so called after the wooden block used to a hold a prisoner's ankles in place, after which they are beaten on the soles of their feet with a bullwhip or a cane, often until they bleed. It's favoured as a method of extremely painful torture that leaves few marks.
Ghosting is also popular, where prisoners are suspended by the wrists from metal grates, sometimes with their feet barely touching the ground. Prisoners can then be flogged or just left in the crucifix-like position for hours at a time.
The latest allegation of Jordanian torture to reach British newspapers came in May. Four anti-regime demonstrators claimed they had had been stripped naked, severely beaten and sexually humiliated while in custody in Amman.
The allegations came days after Theresa May claimed she had received assurances that Jordan will "bend over backwards" to ensure Qatada receives a fair trial.
Lawyer Roger Smith, Director of JUSTICE, thinks this is highly improbable.
"Every agency that has looked at Jordan's human rights record has had severe reservations" he told the Huffington Post UK
"Any prosecution has to be based on evidence from around 1990s so I think it's very difficult to see how they could now get new and untainted evidence."
Although former co-defendants - Al-Hamasher and Abu Hawsher in the Abu Qatada case have now been pardoned, they continue to have the threat of imprisonment hang over them and have been re-arrested several times.
Amnesty International insisted that Abu Qatada himself faced a "very real threat" of being tortured if he was deported.
"The UK should not send anyone into the hands of torturers " the organisation said, adding: "Should the UK authorities genuinely believe that Abu Qatada has committed a criminal offence, they should either put him on trial in this country or extradite him to a third country that can safely and fairly do so."
On Wednesday, a senior immigration judge said the evidence the Jordanian government had against terror suspect Abu Qatada was "extremely thin". The latest appeal is being held specifically to test the assurances offered by Jordan.
The case against Abu Qatada in the UK has been a 10-year litigious battle fraught with political wrangling, voracious media coverage and cat and mouse tactics.
Theresa May has been humiliated a number of times over the trial of the 51-year-old radical cleric.
In April the home secretary was put under pressure after the confusion deadline for appeals against the preacher's deportation to Jordan. The legal bill for repeated failed attempts to deport Qatada has now reached over £1m.
However Robin Tam QC, for the Home Secretary told the tribunal on Wednesday that terror suspect Abu Qatada is "scraping the barrel" in an appeal against deportation which "bears all the hallmarks of a last-ditch argument."