The amount of undeclared cash being seized from Chinese citizens at Vancouver International Airport has ballooned in recent years, reaching $6.4 million in 2015 alone.

That’s up from $4.3 million in 2014 and $2.3 million the year before, according to documents obtained by the B.C. NDP through a freedom of information request.

“There’s just been a big spike in money being brought into the country, particularly from China,” said housing critic David Eby.

“When you see 50 per cent increases year over year, that’s a warning and that’s an indication that problem is getting worse, it’s not getting better.”

That seized cash is on top of the $330 million that was declared legally by mainland Chinese citizens at Vancouver’s airport over the last three years, an influx that Eby believes needs to be more thoroughly examined.

“We need to ask where is this money ending up and does it have implications for our tax policy, especially with respect to real estate,” he said.

The cash that was seized from Chinese citizens makes up about 72 per cent of all the undeclared money seized at YVR over the same period. More money is also believed to be slipping into the country unnoticed.

Those millions of dollars aren’t necessarily the proceeds of crime, but once the money arrives in Canada the trail can go cold. Earlier this year, officials warned that Metro Vancouver’s real estate market is at risk of being used for money for laundering.

The federal anti-money laundering agency, Fintrac, conducted more than 80 audits of Lower Mainland real estate offices last summer and found 55 weren’t complying with regulations, including rules that require proper record-keeping and compel agents to flag suspicious transactions.

B.C.’s Ministry of Finance told CTV News the province is currently collaborating with federal and municipal officials to tackle tax evasion and money laundering in real estate.

“We are working with the federal government in identifying strategies to strengthen information sharing among various levels of government, in an effort to prevent tax evasion and money laundering,” a spokesperson said in an email.

When it comes to the millions of undeclared dollars seized at YVR, the money is often returned on appeal, and the maximum fine for first offences is just $250.

With a report from CTV Vancouver’s Tom Popyk