Quebec's anti-corruption unit has announced the end of a lengthy probe into allegations of corruption at the province's real-estate management agency.

Frédérick Gaudreau, the head of the unit known as UPAC, says a decision was made to end the investigation, dubbed "Justesse," without laying any charges.

The probe had looked at ex-Liberal party fundraisers and the head of a provincial real estate agency over alleged kickbacks in return for contracts.

The investigation, which began in 2010 and focused on allegations of corruption, was the subject of a Radio-Canada investigative report in November 2016.​​​​​​

Gaudreau says in a statement released Friday the conditions weren't met to take the accusations further and submit the case to the Crown.

He says the decision was made objectively and with sound management in mind.

Public Security Minister Geneviève Guilbault said she was surprised by the decision.

"This is not the desired outcome," Guilbault said in a tweet, adding however that it was an independent decision by the force.

The unit said in order to protect police its investigation techniques, it won't explain its decision any further.

Guilbault said the province will weigh whether to go ahead with a civil lawsuit in the case.