The Competition and Markets Authority (CMA) has committed to investigate potential mis-selling in the leasehold sector, and estate agents could be among those seen as culpable.

A letter from the CMA to MPs on the Housing, Communities and Local Government Committee said the regulatory body plans to investigate “the extent of any mis-selling and onerous leasehold terms”.

It said: “We propose to use our consumer protection law powers as the most effective way of doing this, rather than by way of a ‘market study’ at this stage, which might in due course lead to our bringing enforcement proceedings if the evidence we uncover would warrant that.

“You will appreciate that at this stage, it would be premature to express a view on whether onerous leasehold terms in fact constitute unfair terms.”

The HCLG Committee had called for the CMA to launch an investigation as part of a parliamentary inquiry into leasehold reform.

The CMA is yet to release the scope of the investigation – which it is believed will be released in the coming weeks – but there are warnings that estate agents should be braced for claims.

It is not clear yet whether the inquiry will apply solely to new leasehold sales or second-hand ones as well.

A CMA spokesman added: “The select committee has raised serious concerns that many home owners who buy long leasehold property don’t know exactly what they are signing up to, and may be trapped in contracts with unfair terms once they move in.

“We have committed to investigating whether these home owners are being hit with expensive fees or unfair contract terms, as well as being given all the information they need before signing on the dotted line. We will set out the full terms of this work when it begins.”

Activists at the National Leasehold Campaign have backed the investigation and said in a statement provided to EYE: “Estate agents need to know exactly what they are selling.

“Otherwise they could leave themselves open to accusations of misrepresentation and it is definitely something they should be concerned about.”

Sebastian O’Kelly, spokesman for the Leasehold Knowledge Partnership campaign group, said developers and freeholders should take primary responsibility but added that estate agents should be in the scope of the inquiry.

O’Kelly said: “Anybody who sold these properties should be part of the inquiry, at least for agents’ own benefit so they can understand what has been sold.”

O’Kelly said he was already seeing PPI-style ambulance-chasing firms looking to help home owners with claims against developers, adding: “This is how it should be.

“Developers have cheated their own customers – there are homes that are un-sellable because of this.”

Mark Hayward, chief executive of NAEA Propertymark said he has also seen groups planning legal action.

He told EYE: “If an agent has been involved in the sale of a leasehold property, they’re required to highlight anything that might affect a consumer’s transactional decision, whether it be service charges, onerous ground rents or charges for making alterations to the property.”

Agents and developers in the firing line as MPs call for overhaul of the leasehold system