MSPs have launched an investigation into why millions of pounds in benefits go unclaimed each year ahead of Holyrood taking control of £3.5bn in welfare spending.

The Parliament’s Social Security Committee wants to find out which factors deter people in order to improve uptake.

It will look at whether informations campaigns, technology and automatic payments could help.

Fewer than a third (31%) of families without children who were eligible for Working Tax Credit claimed it in 2016-17, figures from HMRC and the UK Department for Work and Pensions estimate, and only 60% of those eligible for Pension Credit signed up for it.

Difficulties in estimating the numbers not taking up benefits means the extent of the problem is unknown.

Committee convener Bob Doris said: “There can be any number of reasons for low benefit uptake rates, but it is absolutely essential that we learn the scale of this challenge and take every possible action to improve uptake.

“There is no doubt the stigma of claiming benefits hinders uptake, while too often people are simply not aware of the benefits. Everything must be done to ensure those in need receive the full benefits they’re entitled to.”

Nina Ballantyne of Citizens Advice Scotland added: “In our experience the reasons include stigma, difficulty of the application system, including digital barriers, and low awareness of particular benefits or eligibility. We are pleased MSPs are going to look into the issue, and we will be keen to work with them in this and to submit further evidence.”

The evidence gathering runs to October 21.