Ahead of a visit last month to Poland by the pope, with security extremely high, Polish police arrested an Iraqi man for possessing "trace amounts" of an explosive. A month later, the man is still in a Polish prison and his father is appealing for his release, insisting that his son is innocent and that the suspicious material was nothing more than a bit of paint on his suitcase.

"He is a good man, athletic, and artistic. He is not even religious. He is not seeking to harm anyone," Ahmed Al-Haboubi said of his son, Sinan Al-Haboubi, in an interview with The Associated Press in Cairo. "He is a peaceful guy."

Sinan Al-Haboubi, 48, was arrested on July 21 in the central Polish city of Lodz on charges of possessing explosives, a crime that carries a prison sentence ranging from six months to eight years. A spokeswoman for prosecutors, Ewa Bialik, told the AP this week that Al-Haboubi had "trace amounts of organic chemical compounds."

The country's Internal Security Agency, which handles matters of terrorism, is involved in the investigation and authorities have refused to give more details about the case, which they are treating as highly classified.

The father, once a government minister who fled Saddam Hussain's takeover of the country in the 1970s, said that chemical came from a bit of paint on his son's luggage.

"His suitcase hit the wall, and it scratched some paint onto it. They analyzed it as if it had traces of something, I think something that is from the production of the paint," he told the AP. "This cannot be evidence."

The arrest came as Polish security officials were on high alert following a string of extremist attacks in Western Europe, and as the country imposed tight security at borders and across the country ahead of a visit by Pope Francis to Krakow from July 27-31.

Two others, a Tunisian and an Algerian, were also arrested in that period. Justice Minister Zbigniew Ziobro said they were all treated as "possible terrorist threats." The Tunisian and Algerian have since been released without charge.

Ahmed Al-Haboubi said that his son, an electronic engineer by training, had been living for the past 16 years in Switzerland, where he had received asylum, and was traveling around Poland to find a place to start a business. A diplomat in the family once posted to Poland was partial inspiration for his son's move, as was his appreciation for the country's beauty, he said.

"He was looking for a place to settle and start his own work; he wanted to open a business, something simple like a pizza shop," Ahmed Al-Haboubi said.

He added that the timing proved unfortunate, and "it seems that Polish authorities have Islamophobia, a negative attitude toward Arabs and Muslims."

Poland's right-wing ruling party, Law and Justice, came to power last year on a strongly anti-migrant message. The government has refused to accept any migrants in a European Union plan to settle refugees across the continent. Many Poles strongly oppose accepting Muslims, seeing them as threats to security and the country's strong Catholic identity. In recent months there have also been xenophobic attacks against Arabs or people with dark skin.

Al-Haboubi has also sent a letter to Polish authorities telling them that his son comes from a Shiite family, stressing that he could not have connections to the Islamic State group or other extremist organizations, which are based on the Sunni branch of Islam.

"Sinan belongs to a prominent Shia family which has been known for its intellectual and cultural activities and has no connection to extremism," he wrote in a letter addressed to the Polish president, prime minister, foreign minister and interior minister, and which he shared with the AP. "In no way Sinan can have links or any kind of connections to radical or extremist groups."

Al-Haboubi's lawyer, Lukasz Banatkiewicz, said that he is seeking the release of Al-Haboubi, who is in a prison in the central Polish city of Piotrkow Trybulanski, not far from Lodz, where he was arrested. He is in a two-month preventative detention which ends Sept. 19. Authorities have not said if they will seek to extend the detention.

"He said he is not guilty and, as his attorney, I can say that the evidence to date is insufficient to accuse him and for sure it's not enough to put him in detention," Banatkiewicz told the AP.