* Rights groups say CIA ran secret jails in Poland
* Poland denies this, says conducting fair investigation
* Alleged detainee files appeal to European court
* Application says delays could allow for cover-up
Delays in Poland's investigation into whether the CIA ran secret jails on its soil could have caused evidence to be lost and given security services time to cover their tracks, according to a submission to the European Court of Human Rights.
Lawyers for Saudi-born Abu Zubaydah, who alleges he was held illegally by the CIA in Poland, on Tuesday submitted an application the court to hear their client's case. They argued there was no hope of him receiving fair treatment inside Poland.
Poland is the only country known to be conducting a criminal investigation into so-called "black sites" - the secret facilities in foreign countries where CIA agents detained and interrogated people they believed were al Qaeda militants.
But the investigation has been running for five years and there is no sign that anyone is close to being put on trial. Human rights groups accuse Poland of deliberately drawing out the investigation to avoid prosecuting senior politicians and embarrassing its U.S. allies. It denies the allegation.
"Poland's lack of promptness may have had an impact on its (the investigation's) effectiveness in numerous ways," Zubaydah's lawyers wrote in their 87-page submission to the Strasbourg-based court.
It said the possible consequences included "the loss of fresh evidence such as forensic evidence from the rendition sites and 'black sites', allowing the possibility of cover-up or obstruction by the security services, and prejudicing the availability of domestic remedies through the loss of witness and physical evidence".
It was not clear if, by security services, the lawyers were referring to the CIA, Poland's own agencies, or both.
According to rights groups and the Council of Europe, al Qaeda suspects were flown in secret to a remote Polish airfield between 2002 and 2005 and then transported to an intelligence academy near a village called Stare Kiejkuty.
Here, on the edge of a lake and surrounded by forest, rights campaigners say, the detainees were subjected to interrogation techniques which amounted to torture.
Zubaydah is now held at Guantanamo Bay, the U.S. military prison in Cuba. He has been granted the status of victim in the Polish criminal investigation, giving his legal representatives the right to be briefed on certain aspects of the case.
NO PENS ALLOWED
Polish officials deny that the CIA operated jails on Polish soil. They say they are conducting a full and fair investigation, free of any political pressure, but that some details have to stay secret to avoid exposing intelligence agents to attacks by al Qaeda sympathisers.
Prosecutors say the delays have happened because the investigation is complex, and because the U.S. government has turned down requests for information.
The application to the court in Strasbourg said that a Polish lawyer for Zubaydah has been denied the access to the investigation files he needs to properly represent his client.
It said he had only been allowed to see a small part of the case files, which are kept in the prosecutor's office in the southern Polish city of Krakow.
When he can view the files, it said, he is not allowed to make notes on his laptop or even use a pen. He is forbidden from sharing his knowledge of the files with anyone, and cannot make legal submissions based on what he has read in them.
Around the time he was captured in Pakistan, the U.S. government said Zubaydah had run a camp in Afghanistan that trained some of those who carried out the Sept. 11, 2001 attacks on the United States. He has not been prosecuted.
If the European court accepts Zubaydah's case, it is likely to be several years before it makes a ruling. If it were to rule in his favour, it could award him damages and find Poland in violation of European law, embarrassing the country's rulers.
The court is already hearing the case of another man who alleges he was held in a CIA jail in Poland, Saudi national Abd al-Rahim al-Nashiri. Poland has not answered questions about his case which the court put to it eight months ago.