Almost one in five Scots have not told their partner the full extent of their debts, according to new research.

The study, conducted on behalf of the Debt Advisory Centre, found nearly two-thirds of Scots in a relationship have unsecured debt, with £3,400 the average amount owed.

It found 17% of those questioned said their partner is not aware of the full extent of their borrowing.

And almost one in 10 (7%) admitted they do not know if their partner has any unsecured debt.

While the average amount owed is £3,400, the survey found more than a fifth owe more than £5,000.

More than a third of respondents said they hide debt out of embarrassment, however money experts advised couples to be open about their finances.

Melanie Taylor, spokeswoman for the Debt Advisory Centre, said: "Discussing finances, especially debts, can be daunting, especially in a new relationship. However, hiding debt from your spouse or fiance is storing up a problem that could seriously threaten the future security and happiness of both of you.

"Once plans turn to marriage, it's essential that you understand each other's financial position and that includes any debt that you bring into the marriage.

"I would advise setting aside time to go through your finances together and to put in place clear plans to manage money, including household budgeting and paying off debt.

"And if you are worried about the amount that you owe, then seek professional advice together. Feeling worried about money is bound to seep into your relationship, so don't struggle on your own."

Almost two-thirds of those who plan to get married said they owe money on credit cards, loans and overdrafts.

And almost a third of Scots who are married or planning to get married said they do not feel it is important to tell their partner about their debts at all, while 5% of those questioned feel it is best to wait until after the honeymoon before revealing any debts.

The Debt Advisory Centre said it had helped "hundreds of thousands of people" tackle debt problems since it was set up in 1993, and it is currently working with 70,000 customers in debt.

Sara Davison, a break-up and divorce councillor, said honesty around finances is needed and ignoring money issues can cause "irreparable" damage to relationships.

"It's natural to want to show your best side to your future spouse so it can be tempting to hide any debt issues you may have," Ms Davison said.

"However, it's important to remember that honesty is key to a long lasting and happy partnership.

"Money problems put a lot of stress on relationships and if the information was withheld it can cause huge trust issues. Financial challenges can be overcome if dealt with properly. However, if you sweep them under the carpet the damage to your marriage may be irreparable.

"I see many clients in my clinic who believe their problems started with disagreements over money, and the frustration and resentment built-up and spread to other areas of their relationship, driving them further and further apart.

"It's always best to face up to your true financial situation and deal with any embarrassment before you take your wedding vows. If they are the partner for you, they will work with you to find a solution. If not, then better you know now than face the divorce courts later on."

The research, carried out by Red Dot, questioned 2,000 adults aged 18 and over between July 17 and July 23, of whom 634 were Scottish residents.