A growing number of Shanghai residents are hiring private detectives to investigate their future spouse before walking down the aisle, say Chinese media.

Detectives will look into a potential spouse’s education, criminal record, finances, family background, health and even talk to friends and co-workers to learn about the person’s personality.

An investigation usually lasts one to two weeks depending on the client’s requirements.

Investigation techniques extend from following the future spouse to some complicated methods, according to George Huang, a spokesperson for Shanghai Tondorer Private Detective Company.

"We will find out what they do in their spare time," said Huang. "Just to see if they go to any places they shouldn’t."

Sometimes the agents will find a way to socialize with the person’s friends.

"Impressions from these people’s close friends and co-workers are also crucial to our investigation," said Huang.

Photographs and video cameras are also used when necessary.

"Our clients want to make sure they are marrying the right person," said Huang. "They need to know their partners are faithful."

Some parents hire the service behind their children’s backs, said Luo Tian, a manager at Da Shanghai Private Detective Investigation.

The parents can’t trust their children’s fiancees.

"Marriage is no kid’s play," said Huang. "Those parents just hope to see their children make the right choices."

A recent online poll suggests a large number of locals support the service.

Among 3,338 respondents, 1,908 said they would use the service, as society has made people too superficial and untrustworthy.

The other 1,430 voters said marriages should be based on trust.

They would rather not get married than pay for some cloak-and-dagger services.

"Nowadays people are less confident in socializing," said Liu Jun, a psychology therapist at the Shanghai Ruoqin Psychology Therapy Centre.

"To protect themselves, they incline to the negative aspects of an issue.

Once the shortcomings are noted, they will back up right away."

Liu said some people think hiring a detective is a shortcut to a trusting relationship.

He said online dating and cyber chat also weakened people’s ability to trust.

Liu also agrees that such investigation clears up certain relationship blind spots, such as the relationship between their partners’ parents.

"Since lots of people’s marriages are similar copies of their parents, it’s essential to know about the family background," said Liu.