A campaign to stop letting agents charging "unlawful and exploitative" fees has been launched by a housing charity.

Scotland has an estimated 500 letting agents, involved in around 150,000 private lets each year.

According to Shelter Scotland, 90% of agents it contacted demand fees from those seeking a new home. Prospective tenants can face fees for credit checks, reference checks or even for checking a property's inventory.

Shelter Scotland believes such fees are unlawful under section 82 of the Rent (Scotland) Act 1984, with an investigation by the charity revealing people were facing charges of as much as £180 from some agents.

Its new website, part of a Reclaim Your Fees campaign, provides advice on what letting agents can and cannot lawfully charge for, as well as sample letters for those seeking a refund and information on how to take a case to the small claims court.

Shelter Scotland director Graeme Brown said: "Over 272,650 families and individuals in Scotland call the private rented sector home, and that number is rising.

"That some letting agents, established and new, are routinely ripping off tenants by charging extortionate and unjustified upfront fees is shocking and, quite simply, exploitative."

He added: "They are not only ripping off people who need a roof over their head and who, in many cases, have little or no choice but to pay up, but they are also undermining the work of good letting agents who offer a fair deal to tenants."

Mr Brown said: "We hope that the Reclaim Your Fees team and website will help private tenants to claim a refund for charges made unlawfully by their letting agent.

"Nevertheless, that is not a long-term solution. We want the Scottish Government to explicitly clarify legislation to make it clear to tenants, landlords and their agents that all charges above rent and a reasonable deposit are unlawful. Only then will tenants, and indeed landlords, be assured that they are not being exploited."

A Scottish Government spokesman said: "The majority of Scotland's 500 letting agents operate in a professional manner. Nevertheless, we are aware that concern exists in relation to the legality of pre-tenancy charges made by some agents.

"That is why the Housing Minister Keith Brown recently launched a consultation which presents options on how the law can be clarified to deal with unfair and illegal premiums that can prove a barrier to people getting into rented accommodation."

For more information, visit Shelter Scotland's Reclaim Your Fees website.