The Competition and Markets Authority (CMA) has apparently "spotted" problems in the sector and the regulator has been investigating the issue for the past six months.
Housing Secretary Michael Gove wrote to the Competition and Markets Authority last year asking it to investigate the sector in order to boost supply.
He argued that it had been 14 years since an investigation had been carried out and that it was overdue.
The regulator has spoken to developers, homeowners and local authorities.
Sarah Cardell, chief executive of the CMA, says: The CMA alone cannot solve the problems in the UK housing market.
But we have a role to play and will do our bit to help ensure that the private rented and housebuilding markets work better for people and businesses.
Another hot issue on the agenda was charging landlords for homes built in residential areas.
Concerns raised with the CMA about the private rented sector include deposit-free schemes, where tenants do not have to pay a deposit but may be subject to other liabilities.
Another concern is that tenants are being offered bogus licences rather than secure tenancies.
Finally, the CMA is also investigating landlords discriminating against tenants on benefits.