Almost two-thirds of tenants (60%) said they have found it difficult to get their deposits returned from landlords.

That is according to a Red C survey for the the Union of Students in Ireland (USI), which questioned more than 1,000 people over the age of 18.

It says there is 40% less rental space available than there was this time last year - while rents have increased by over 8% nationally, and much more in cities, according to Daft.ie.

The USI has re-launched its room rental registration site homes.usi.ie and urged people with spare rooms to let them out to students. 

Under the government’s rent-a-room scheme, homeowners don’t have to pay tax on rental income earned from digs unless it exceeds a yearly cap of €12,000.

Rosalind Carroll of the Residential Tenancies Board told Newstalk Breakfast that anyone with deposit issues can seek guidance on their website, rtb.ie, or call them on 0818-30-30-37. 

She said any number of reasons could see a deposit being withheld.

"The first thing we'd be saying to people and to landlords particularly is, you need to think about...what was the condition of the property when it first went in - were the units old in the property in the first place, or were they new - and how many occupants did you expect to be in the dwelling?

"If you're going to rent to one person, you'd have less wear and tear, whereas if you're renting to five or six individuals in the house you have to, as a landlord, expect further wear and tear."

She also recommended that tenants take photos of everything they can when they first move in.

Meanwhile, Ministers Simon Coveney and Damien English have announced the allocation of €49,000 to the USI  to support their appointment of a student housing officer.

The nine-month role is being created to help identify additional accommodation, including digs and rooms in private homes, to ease the pressure on securing rented accommodation ahead of the next academic year.