It is impossible to miss the big blue banner hanging across the front of the modern office building near the soccer stadium in the centre of Shenyang in north-east China. It reads: "We will help you realise your dream to study abroad. Call in to see us."

Ms the Heng Ge Lai education placement agency. "That is where my nightmare started. We had no idea of what was ahead when we went there," the widow says bitterly.

Agents who place Chinese students abroad, such as this one in Shenyang, an industrial city of seven million people in Liaoning Province, can be found all over the north-east. Chinese students dream of learning English, or doing postgraduate studies in North America or Europe.

Ireland, with its image as a friendly country, and a good reputation for English, is a popular study destination. There are approximately 10,000 Chinese students currently in Ireland on study visas. Every morning students can be seen queueing for their visas outside the Embassy in Beijing.

Ms Song Xiumei's daughter, Liu Quing (19), and her boyfriend, Feng Yue (19), chased that European dream. Quing arrived in Ireland to take up a place at the Swan Training Centre in Grafton Street in March 2000. Yue followed two months later and enrolled in the Centre for English Studies in Dame Street. They loved Dublin and were happy.

On March 14th the two young people were found strangled and burned in their apartment in Blackhall Square off North King Street in Dublin. A Chinese national has been charged with their murders and is in custody. Almost six months on, both families have still not come to terms with what happened and are no nearer to learning the motive for the killings.

Both Liu Quing and Feng Yue were excellent students. They never gave their families any trouble. Quing's father died of a heart attack when she was three, leaving her mother, a tax official, to rear her single-handed. Her talented daughter was her pride and joy. "She was my whole life. We were very happy," Ms Xiumei told The Irish Times this week.

Mother and daughter lived in Jiamusi City in Heilongjiang Province, next to Liaoning. When Quing was 15, she moved to Shenyang to attend senior middle school. She lived with her aunt and uncle who were like parents to the girl. "She was bright and intelligent and everyone loved her. She was very popular and had lots of friends," her uncle, Mr Song Shoutian, said.

In senior middle school, Quing met Feng Yue. His parents are divorced and he lived with his mother in Shenyang. He had a seven-year-old stepbrother, from his father's new relationship. His father is president of a petroleum company, and the family is well off. Both students planned to go to Europe to study English before they started their university degrees in China. Quing was interested in doing law; Feng was undecided.

In Quing's bedroom in her uncle's apartment in Shenyang there is an atlas on the wall. "She wanted to see the world and we bought her this map," he said, pointing to Ireland. "As big as the world is, she wanted to go to Ireland to learn English. She heard so many nice things about your country."

Quing organised her English-language training in Ireland through the Heng Ge Lai agency. The fee to the agency to look after the complicated procedure from start to finish, including getting the student visa, was £800.

The college fee was £2,000 and had to be paid upfront. Bank statements had to be produced proving there was enough money to sustain Quing in Dublin. Her mother emptied her life savings, and money was borrowed from several family members to raise $15,000.

Feng Yue was in a different position. He didn't get his visa through an agent but went about it independently. He produced a bank statement with $30,000 to prove he had the means to sustain himself in Ireland and to pay fees, according to his uncle, Mr Yue Lian Jun.

Both students loved Dublin. Feng worked one night a week in a pub in Ballinteer. "He had enough money. He did not need to work any more than that. He was in Ireland to learn English and not to work," according to his mother, Ms Shi Weihua. Quing worked several nights a week in the Bangkok Cafe to raise extra money.

The couple travelled to China at the end of January to spend the Chinese New Year with their families. They spoke glowingly of Ireland. Feng Yue's mother finds it hard to speak of her son and has been suffering from depression since his murder. "He was so happy when he came home. Very contented. There was no indication that there was anything wrong."

They returned to Dublin at the end of February. They both called home to say they had arrived safely. The next the families heard was that they had been brutally murdered in their apartment.

Members of both families flew to Dublin to look after funeral arrangements and to try and establish why the tragedy happened. The Chinese embassy was extremely helpful, and initially there was a lot of contact with the Garda.

But both families, who have been brought close together by this tragedy, are angry that six months on they are no wiser as to why their children died.

"We know somebody has been charged, but still we have not heard from the police authorities in months, even though we wrote to them in April asking for more information. We also want compensation. Your Government had a responsibility for our children's safety," said Mr Song Shoutian.

Quing's mother said that in China, due to the one-child policy, children are precious. "Mothers give everything to their children. When they are taken away like this for no explained reason, it is very hard to cope".

The families are also concerned at the fact that both students' bank accounts were empty when they went with gardai to close them last March. Feng's mother said when he went back to Ireland at the end of February he had $4,300 with him. There was only £70 in the bank account in Dublin when he died two weeks later. Li Quing's mother estimates her daughter should have had several thousand dollars in her account.

"We want to know what happened to the money. We want access to bank records showing when the money was withdrawn".

They would caution other Chinese students about going to Ireland to study until the full facts of this case are cleared up. Feng Yue's cousin was due to go to Ireland in April. She had her language-school fees paid and her visa secured. Her father, Mr Yue Lian Jun, showed me her passport with the visa stamp. She cancelled her plans after what happened.

"We have great respect for your country and your people, but you can understand how we feel after what happened us," he said.

The Chinese and Irish criminal justice systems are different. It is hard for the families to understand that before a trial in Dublin a book of evidence has to be put together and a case prepared. Only when the trial happens will the full story emerge and will all their questions be answered.

According to a Garda spokesman, it could be another year before the case comes to court for hearing. He said the Garda had a lot of contact with the family initially and could understand their frustration that despite the fact that a man has been charged, the case does not seem to be moving forward.

Before I left, Liu Quing's mother asked: "Do you have executions in Ireland?"

"No," I replied.

"But how do you punish people in your country who takes the life of another? Whoever is guilty of this crime deserves to die. And even then that will be only one life for two."