The son of a Canadian couple detained in China has arrived back in the country to find out more about his parents' case.

Simeon Garratt's trip has been timed to coincide with a state visit by Prime Minister Stephen Harper, who is on his third trip to China to meet with business leaders about increasing trade between the two countries.

Garratt said that, since he arrived, he's been able to meet with Canadian officials at the embassy in Beijing, but he has not been able to learn much more about his parents' case.

"The government has been very helpful. Foreign Affairs has been great. But there's only so much information that we're privy to," he told CTV's Canada AM from Beijing Friday.

"A lot of these discussions are happening at a very high level. So it's sort of expected we're not going to get access to everything."

Garratt said he left the embassy meeting knowing that his concerns are being raised "at very high levels," with several branches of the Canadian government.

But he won’t get a chance to raise those concerns at the highest level himself, as a letter he sent to the Prime Minister’s Office remains unanswered.

“If there’s anybody out there that’s going to be able to help my parents, it’s him,†Garratt said of Harper in a separate interview Friday with CTV’s Asia Bureau Chief Janis Mackey Frayer.

Garratt's parents, Kevin and Julia Garratt, were detained in August on suspicion of spying. They've lived and worked in China for the last 30 years, running a cafe since 2008. While they haven't been officially arrested, they have been interrogated repeatedly.

The Garratt family’s lawyer, James Zimmerman, says their case must be addressed before Canada and China can move ahead with their business ventures.

“It’s almost impossible for the two countries to move forward until this case is resolved,†he said Friday.

The couple lives in the northern city of Dandong, which is close to the North Korean border. Chinese state media report the couple is suspected of stealing national secrets about military and national defence research.

Garratt says the accusations are crazy.

"'Absurd' I think is the word I used initially. It sort of blew my mind," he said about hearing the accusations for the first time. "Anybody who knows them thinks it's a bit outrageous."

Garratt has not been able to speak with his parents since his arrival, nor during the last 95 days. He also has not had any contact with Chinese authorities. Canadian consular officials have been able to visit the couple every two weeks, but have not learned much more about what is next for the couple.

Garratt says his parents are being held in Dandong, in separate places, so they don't have contact with each other, and are only getting 30 minutes of time outside per day. He says he last spoke to them the night they were detained.

"They were going out to dinner and we were sending text messages back and forth. That was 95 days ago," he said.

Garratt, who was born in China and now lives in Vancouver, said he never expected his parents' detention would go on this long, and that's part of what spurred his decision to return to the country.

"It's been very hard for my whole family. It's a very stressful situation. And part of the reason I'm here is hopefully to get some answers."

Garratt says he plans to sell the coffee shop his parents kept in Dandong.

With a report by CTV’s Asia Bureau Chief Janis Mackey Frayer in Beijing