Leeds University Union (LUU) says tens of thousands of pounds remain owed and more people come forward every week to report a dispute over unreturned deposits.

Many of the complaints centre on Leeds-based Providence Properties and Providence Lets.

One parent whose daughter has been waiting 14 months for the return of £250 from Providence Properties said he was now considering taking the dispute to county court. Housing officials at the university say that some students have won their county court cases but are still waiting for their money.

Students waiting for their cash back say they did everything their landlord asked of them, such as settling up bills and cleaning the property, but are still waiting for their money.

The companies involved have denied the allegations and say no one is owed any money.

Last night Andrea Kerslake, LUU housing manager, said the deposits had been held with Providence Lets after students had signed contracts with Providence Properties.

She said deposits had not been returned and in most cases there had been no explanation why.

"I am aware of court action being taken where judgments have been awarded in favour of the students but to date payments have not been made."

She said 72 students were still owed almost £20,000 from last year.

She said: "We are also receiving new complaints from students who vacated properties since July.

"In the past few weeks alone we have received complaints from approximately eight households – this could involve nearly 40 students paying an average deposit of £300.

"New complaints are being received almost on a daily basis. This gives us great concern for the security of money students have paid under contracts signed with Providence Properties."

She said Providence Lets had failed to respond to correspondence with the LUU.

"We even have one case where money has been promised over three months ago but to date no cheques have been received."

From April 2007 all deposit money taken must be protected in one of the three Government schemes, she said.

"We would strongly advise students to check with the scheme operators that their money has been protected. It is a criminal offence for deposits not to be protected and students could take court action to claim up to three times the amount of their deposits if the landlord has not used one of the schemes."

A spokesman for Providence Properties said the allegations about unreturned deposits were "untrue and unfounded".

Asked how many deposits had been withheld, he said "it's basically nil" before adding: "If there are any disputes they lie with damages. Students may cause damage or not pay their bills."

Leeds North West MP Greg Mulholland called last night for the Government to extend the deposit protection scheme to cover people who fail to get deposits returned.

He said last night: "It is totally unacceptable that so many people are still finding it hard to get deposits back and it is clear that some companies are still wrongly withholding them."