Sport Wales risked damaging its reputation in the way it awarded contracts, an internal audit has found.
Accountants Deloitte said a consultant was given the specifications for a tender two days before his competitors.
It also recommended rule changes to its declarations of interest after considering a research firm contract.
Sport Wales - whose chairman and vice-chairwoman remain suspended amid concerns its board was dysfunctional - accepted the report.
But the body, which promotes and distributes money for elite and grassroots sport, said Deloitte found no impropriety.
Sam Whale, managing director of a firm called Unforgiving Minute, won a £33,600 contract in April 2016 to mentor Sport Wales staff.
The Deloitte report said he was given the tender specification by Sport Wales chief Sarah Powell on 4 April, two days before other bidders.
Emailing Sport Wales staff members on 4 April, Ms Powell said she was in the process of confirming Mr Whale's contract.
The email is one of a series seen by BBC Wales, including correspondence between the two discussing the terms of the contract, including work locations, timelines and prices, nearly a month before it went out to tender.
It culminates in an email, two days before the rest of the tender emails were sent, from Ms Powell to Mr Whale which said: "I'm still not 100% sure how we are going to finalise this tender but if you could provide us with a submission based on this I can at least get this moving in our system here.
"I was thinking if we did this I can send to a couple of people and apologise for the short notice but this is where we are and see who comes back?"
Unforgiving Minute was the only tender as the other companies were unable to respond within the required time frame.
Deloitte's report, leaked to BBC Wales, said: "There is a risk that there may be a perception of some bidders being given undue advantage during the tender process which may be perceived as undermining the spirit of transparency for public procurement."
There was no response from Mr Whale when contacted by BBC Wales. There was also no suggestion of impropriety by him in the report.
Deloitte also looked at four contracts, worth a total of £71,000, awarded to Beaufort Research since 2011.
The accountants said three out of four relevant tender evaluation forms could not be located, meaning Deloitte was unable to determine who was involved in assessing the tenders.
'Transparency and fairness'
Deloitte described the lack of documentation as an oversight but said there was evidence elsewhere that proper procedures were being followed.
The managing director of Beaufort Research is Fiona McAllister, sister of the then chairwoman of Sport Wales, Laura McAllister.
Deloitte said there was no evidence the chairwoman was involved in the decision-making process but that, while earlier declarations of interest were made by Laura McAllister, she had not done so since 2013.
However, Sport Wales staff are only asked to declare interests of immediate family members, which does not include siblings, and Deloitte said Sport Wales may want to consider using a broader definition.
Beaufort Research also failed to make any explicit declaration of interest, even though the tender document asked it to make known any relevant conflicts of interest.
The report said: "There is a risk that the principle of transparency and fairness may be perceived to be undermined, resulting in reputational damage to Sport Wales if perceived conflicts of interest are not declared."
Laura McAllister said: "As confirmed by the internal auditors, all declarations of interest were made by me as chair in accordance with guidelines, in full at all times.
"Clearly, there would be no involvement from a board chair in contract awards of any kind."
Fiona McAllister said Beaufort Research "submitted a large number of tenders to Sport Wales, winning some contracts and losing others, but always via a competitive and rigorous procurement process".
"I was not involved in the bid team for the four contracts awarded since 2011 or in carrying out any of the research for these contracts," she added.
"Beaufort has always dealt with the Sport Wales research and evaluation team on tenders and projects, never with the chair or any of the board members.
"Therefore we did not believe there was a need to declare a conflict of interest."
A Sport Wales spokesman said: "This report made a number of recommendations relating to the procurement of external consultants across the organisation and identified a number of areas where procedures could be improved.
"As a result of these recommendations a set of management responses were provided to and accepted by Deloitte.
"Those responses were endorsed by the Sport Wales audit and risk committee at their meeting on 10 March 2017.
"At no point in this report do Deloitte suggest any impropriety on the part of staff within Sport Wales."
Welsh Conservative spokesman on sport, Russell George, said Sport Wales reputation was being "harmed by each revelation", saying ministers had to "consider its future very carefully".