The man suspected of killing Scottish aid worker Elisabeth Jane Ross in Greece is 26-year-old Sharif Ahmadzai, the BBC understands.

He was arrested after the body of the 38-year-old was found in a suitcase in an abandoned building in the Kypseli district of Athens on 18 July, several days after she was reported missing.

Ahmadzai, who was born in Afghanistan and is a champion boxer, settled in Greece after travelling there as a teenager.

Both Ross and Ahmadzai had worked with refugees and Greek police are investigating whether the pair knew each other through the charity sector.

Ahmadzai was arrested on suspicion of homicide with intent, robbery and weapons offences, and is expected to appear in court in Athens on Wednesday.

Police said the coroner’s initial report failed to determine a cause of death, but more detailed examinations concluded it was an “obvious criminal act, likely asphyxiation”.

The BBC understands Ahmadzai, who left Afghanistan after being orphaned aged 15, lives in Greece with his American wife, Alaina Hall, and their child.

His father, a commander in the Afghan army, was shot dead and his mother and siblings were killed by a suicide bomber in Kabul.

He travelled to Greece via Iran and Turkey, according to a video telling his story which was published by the International Federation of Red Cross and Red Crescent Societies (IFRC), before settling in a refugee camp on the island of Lesbos.

It is understood this is where he met his wife and converted to Christianity. The couple then set up the charity Love Every Nation Athens to help other refugees.

Police said Elisabeth Jane Ross – who is from Edinburgh and is known to family and friends as Lisa – arrived in Greece on 26 June and stayed in the Kertasini area of Piraeus until 10 July.

She had been volunteering with a refugee support group based in Athens.

Ross told Greek friends that she was going to Kypseli to meet “American friends” on 15 July.

The president of the Union of Police Officers of Southeast Attica, George Kalliakmanis, said they were investigating whether Ahmadzai had a key to the apartment Ross was staying in.

The police union said it had verified footage appearing to show Ahmadzai carrying a suitcase which is believed to have contained the body.

It added that a location sharing app, used by Ahmadzai’s wife, showed that the suspect was at 9 Rethymnou Street – the place where Ross is thought to have died – in the days before.

Police also said the suspect had used the dead woman’s bank cards to withdraw money.

The building the body was found in is about 20 minutes from where Ross had been staying.

In an interview with BBC News, Kalliakmanis said: “They [police investigators] are looking into whether he [Ahmadzai] had met her [Ross] previously through his involvement in boxing or an NGO working with refugees, as she also worked for an NGO.

“Could they have crossed paths in the past? Yes, it’s possible.”

Kalliakmanis said Ahmadzai had denied murder but admitted to moving the body.

“He claims he found her dead in the bathroom and panicked, fearing he would be blamed,” he said.

Kalliakmanis said police believed the suspect took the victim’s bank card and phone, and “made sure” to send text messages to her family and friends to “make it seem like she was still alive”.

He said the police also believed the suspect used the victim’s bank card to make withdrawals totalling “around €10,000”.

Kalliakmanis added that Ahmadzai’s wife had no involvement or prior knowledge of the alleged crime.

Flowers have been laid near to where her body was discovered.

One message reads: “For Elisabeth, May you rest in peace and may your memory live on in the hearts of us all. With deepest sympathy and respect. You will not be forgotten.”

In Edinburgh, Pastor Peter Anderson said Ross had been a “precious” member of the congregation at City on a Hill church for 20 years.

He described her as having a “big passion” for missionary work and “cared for people all over the world”.

In a video posted on the City on a Hill Facebook page, the pastor said: “She had been to many places and served people. She was a very precious girl and it is a tragic loss.”

During searches of Ahmadzai’s home, officers claimed to have recovered and seized a replica pistol and a knife.

Police said they were also looking to trace Ross’s American friends.

Additional reporting by Daphne Toli in Athens and Georgina Hayes in Scotland.